6f1h

C1rC1s complex

Method: X-RAY DIFFRACTION D_max: 155.2 Å Quality: GOOD

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1. Protein Identity and Related Structures Protein Identity & Related Structures

Complement C1r subcomponent

Homo sapiens

State in the Current Structure

Assembly	Oligomeric State	Construct	Mutations and Modifications	Ligands, Ions and Associated Components	Method and Experimental Conditions	Structure Quality
1	Other combination Heteromer Protein × 2 其他Polymer 2 PDB declaration: dimeric（2） Consistent with protein copy count	Chain A； UniProt 18–308	Not recorded	Complement C1s subcomponent × 1 （P09871） ;2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-beta-D-galactopyranose-(1-4)-alpha-D-mannopyranose-(1-3)-[alpha-D-mannopyranose-(1-6)]beta-D-mannopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose ; × 1 beta-D-mannopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose × 1 CA CALCIUM ION × 6 NA SODIUM ION × 3 NAG 2-acetamido-2-deoxy-beta-D-glucopyranose × 1	X-RAY DIFFRACTION X-ray crystallization conditions：VAPOR DIFFUSION, SITTING DROP；pH 8；298 K；12-18% PEG 8000, 100 mM Imidazole at pH 8.0	Resolution 4.50 Å R-free 0.340
2	Other combination Heteromer Protein × 2 其他Polymer 3 PDB declaration: dimeric（2） Consistent with protein copy count	Chain C； UniProt 18–308	Not recorded	Complement C1s subcomponent × 1 （P09871） ;beta-D-galactopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-2)-alpha-D-mannopyranose-(1-3)-[alpha-D-mannopyranose-(1-6)]beta-D-mannopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose ; × 1 beta-D-mannopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose × 2 CA CALCIUM ION × 6 NA SODIUM ION × 3 LYS LYSINE × 1	X-RAY DIFFRACTION X-ray crystallization conditions：VAPOR DIFFUSION, SITTING DROP；pH 8；298 K；12-18% PEG 8000, 100 mM Imidazole at pH 8.0	Resolution 4.50 Å R-free 0.340

Other States of the Same Protein in the Database

Each row is a biological assembly of the same UniProt protein in another PDB entry. The “Difference from current entry” column identifies evidence-level differences; no tag means the currently parsed fields agree.

Other PDB	Difference from Current Entry 6F1H	Assembly / Oligomeric State	Construct	Mutations and Modifications	Ligands, Ions and Non-polymers	Method and Experimental Conditions	Structure Quality
1APQ STRUCTURE OF THE EGF-LIKE MODULE OF HUMAN C1R, NMR, 19 STRUCTURES Deposited 1997-07-22	Different construct Different oligomeric state Different ligand/ion Different experimental method Different experimental conditions Different structure-quality metrics	Assembly 1 Protein monomer Monomer；Protein × 1 PDB declaration: monomeric	Chain A 140–192（53 aa） Fragment：EGF-LIKE MODULE	Not recorded	No recorded non-water small molecule	SOLUTION NMR NMR measurement conditions pH 6.7；288 K	Resolution not provided
1GPZ THE CRYSTAL STRUCTURE OF THE ZYMOGEN CATALYTIC DOMAIN OF COMPLEMENT PROTEASE C1R Deposited 2001-11-15	Different construct Different mutation/modification Different oligomeric state Different ligand/ion Different experimental conditions Different structure-quality metrics	Assembly 1 Other combination Monomer；Protein × 1 PDB declaration: monomeric	Chain A 307–705（399 aa） Fragment：CATALYTIC DOMAIN OF HUMAN C1R, RESIDUES 307-705	Mutation：YES	No recorded non-water small molecule	X-RAY DIFFRACTION X-ray crystallization conditions pH 8.5；293 K；1.5 M AMMONIUM SULFATE, 0.1M TAPS, PH 8.5, AT 20 DEG C.	Resolution 2.90 Å R-free 0.290
1GPZ THE CRYSTAL STRUCTURE OF THE ZYMOGEN CATALYTIC DOMAIN OF COMPLEMENT PROTEASE C1R Deposited 2001-11-15	Different construct Different mutation/modification Different oligomeric state Different ligand/ion Different experimental conditions Different structure-quality metrics	Assembly 2 Other combination Monomer；Protein × 1 PDB declaration: monomeric	Chain B 307–705（399 aa） Fragment：CATALYTIC DOMAIN OF HUMAN C1R, RESIDUES 307-705	Mutation：YES	NAG 2-acetamido-2-deoxy-beta-D-glucopyranose × 1	X-RAY DIFFRACTION X-ray crystallization conditions pH 8.5；293 K；1.5 M AMMONIUM SULFATE, 0.1M TAPS, PH 8.5, AT 20 DEG C.	Resolution 2.90 Å R-free 0.290
1MD7 Monomeric structure of the zymogen of complement protease C1r Deposited 2002-08-07	Different construct Different mutation/modification Different oligomeric state Different ligand/ion Different experimental conditions Different structure-quality metrics	Assembly 1 Protein monomer Monomer；Protein × 1 PDB declaration: monomeric	Chain A 375–702（328 aa） Fragment：C-terminal CCP-SP domain	Mutation：S637A	NAG 2-acetamido-2-deoxy-beta-D-glucopyranose × 1	X-RAY DIFFRACTION X-ray crystallization conditions VAPOR DIFFUSION, HANGING DROP；pH 8.4；293 K；ammonium sulfate, TAPS, pH 8.4, VAPOR DIFFUSION, HANGING DROP, temperature 293K	Resolution 3.20 Å R-free 0.285
1MD8 Monomeric structure of the active catalytic domain of complement protease C1r Deposited 2002-08-07	Different construct Different oligomeric state Different ligand/ion Different experimental conditions Different structure-quality metrics	Assembly 1 Protein monomer Monomer；Protein × 1 PDB declaration: monomeric	Chain A 375–703（329 aa） Fragment：C-terminal CCP-SP domain	Not recorded	No recorded non-water small molecule	X-RAY DIFFRACTION X-ray crystallization conditions VAPOR DIFFUSION, HANGING DROP；pH 8.4；293 K；ammonium sulfate, TAPS, pH 8.4, VAPOR DIFFUSION, HANGING DROP, temperature 293K	Resolution 2.80 Å R-free 0.269
2QY0 Active dimeric structure of the catalytic domain of C1r reveals enzyme-product like contacts Deposited 2007-08-13	Different construct Different mutation/modification Different oligomeric state Different ligand/ion Different experimental conditions Different structure-quality metrics	Assembly 1 Protein homooligomer Homooligomer；Protein × 4 PDB declaration: tetrameric	Chain A 309–463（155 aa） Fragment：Sushi-1 and Sushi-2 domains, CCP1-CCP2 Chain B 464–705（242 aa） Fragment：Peptidase S1 domain Chain C 309–463（155 aa） Fragment：Sushi-1 and Sushi-2 domains, CCP1-CCP2 Chain D 464–705（242 aa） Fragment：Peptidase S1 domain	Not recorded	GOL GLYCEROL × 7	X-RAY DIFFRACTION X-ray crystallization conditions VAPOR DIFFUSION, HANGING DROP；pH 7.4；288 K；14% (w/v) PEG 6000, 0.2 M NaCl, 10% (v/v) glycerol, 0.1 M Tris HCl, pH 7.4, VAPOR DIFFUSION, HANGING DROP, temperature 288K	Resolution 2.60 Å R-free 0.259
6F1C C1rC1s complex Deposited 2017-11-21	Different construct Different mutation/modification Different oligomeric state Different ligand/ion Different experimental conditions Different structure-quality metrics	Assembly 1 Other combination Heteromer；Protein × 4 PDB declaration: tetrameric	Chain A 18–308（291 aa） Chain C 18–308（291 aa）	Not recorded	CA CALCIUM ION × 12 NA SODIUM ION × 6 NAG 2-acetamido-2-deoxy-beta-D-glucopyranose × 2	X-RAY DIFFRACTION X-ray crystallization conditions VAPOR DIFFUSION, SITTING DROP；pH 8；293 K；12-18% PEG 8000, 100 mM Imidazole at pH 8.0	Resolution 4.20 Å R-free 0.305
6F1D CUB2 domain of C1r Deposited 2017-11-21	Different construct Different oligomeric state Different ligand/ion Different experimental conditions Different structure-quality metrics	Assembly 1 Protein monomer Monomer；Protein × 1 PDB declaration: monomeric	Chain A 191–307（117 aa）	Not recorded	CA CALCIUM ION × 1 NA SODIUM ION × 1	X-RAY DIFFRACTION X-ray crystallization conditions VAPOR DIFFUSION, SITTING DROP；pH 8.5；298 K；50 mM Tris-HCl at pH 8.5 containing 25% PEG-8K, 2 mM CaCl2 and 3% 1,6-diaminohexane	Resolution 1.95 Å R-free 0.202
6F39 C1r homodimer CUB1-EGF-CUB2 Deposited 2017-11-28	Different construct Different mutation/modification Different oligomeric state Different ligand/ion Different experimental conditions Different structure-quality metrics	Assembly 1 Other combination Homooligomer；Protein × 2 PDB declaration: dimeric	Chain A 22–306（285 aa） Chain B 22–306（285 aa）	Not recorded	CA CALCIUM ION × 6 NA SODIUM ION × 2 NAG 2-acetamido-2-deoxy-beta-D-glucopyranose × 1	X-RAY DIFFRACTION X-ray crystallization conditions VAPOR DIFFUSION, SITTING DROP；298 K；12-18% PEG 8000, 100 mM Imidazole at pH 8.0	Resolution 5.80 Å R-free 0.338
7MZT Borrelia burgdorferi BBK32-C in complex with an autolytic fragment of human C1r at 4.1A Deposited 2021-05-24	Different construct Different mutation/modification Different oligomeric state Different ligand/ion Different experimental conditions Different structure-quality metrics	Assembly 1 Protein heterocomplex Heteromer；Protein × 3 PDB declaration: trimeric	Chain A 300–463（164 aa） Chain B 464–705（242 aa）	Not recorded	NAG 2-acetamido-2-deoxy-beta-D-glucopyranose × 1	X-RAY DIFFRACTION X-ray crystallization conditions VAPOR DIFFUSION, SITTING DROP；293 K；0.2 M Sodium formate, 27.5% Polyethylene glycol 3,350	Resolution 4.07 Å R-free 0.372
9EKD Structure of a C1r Zymogen Fragment Bound to SALO Deposited 2024-12-02	Different construct Different mutation/modification Different oligomeric state Different ligand/ion Different experimental conditions Different structure-quality metrics	Assembly 1 Protein heterocomplex Heteromer；Protein × 2 PDB declaration: dimeric	Chain C 308–705（398 aa） Fragment：residues 308-705	Mutation：S654A	No recorded non-water small molecule	X-RAY DIFFRACTION X-ray crystallization conditions VAPOR DIFFUSION, HANGING DROP；293 K；0.1 M BIS-TRIS (pH 5.6), 0.2 M ammonium sulfate, 20% (w/v) PEG-3350	Resolution 3.28 Å R-free 0.286
9EKD Structure of a C1r Zymogen Fragment Bound to SALO Deposited 2024-12-02	Different construct Different mutation/modification Different oligomeric state Different ligand/ion Different experimental conditions Different structure-quality metrics	Assembly 2 Protein heterocomplex Heteromer；Protein × 2 PDB declaration: dimeric	Chain D 308–705（398 aa） Fragment：residues 308-705	Mutation：S654A	No recorded non-water small molecule	X-RAY DIFFRACTION X-ray crystallization conditions VAPOR DIFFUSION, HANGING DROP；293 K；0.1 M BIS-TRIS (pH 5.6), 0.2 M ammonium sulfate, 20% (w/v) PEG-3350	Resolution 3.28 Å R-free 0.286
9EKE Structure of a C1r Zymogen Fragment Bound to SALO, Y51F Mutant Deposited 2024-12-02	Different construct Different mutation/modification Different oligomeric state Different ligand/ion Different experimental conditions Different structure-quality metrics	Assembly 1 Protein heterocomplex Heteromer；Protein × 2 PDB declaration: dimeric	Chain C 308–705（398 aa）	Mutation：S654A	No recorded non-water small molecule	X-RAY DIFFRACTION X-ray crystallization conditions VAPOR DIFFUSION, HANGING DROP；293 K；0.2 M ammonium citrate tribasic (pH 7.0), 20% (w/v) PEG-3350	Resolution 3.10 Å R-free 0.278
9EKE Structure of a C1r Zymogen Fragment Bound to SALO, Y51F Mutant Deposited 2024-12-02	Different construct Different mutation/modification Different oligomeric state Different ligand/ion Different experimental conditions Different structure-quality metrics	Assembly 2 Protein heterocomplex Heteromer；Protein × 2 PDB declaration: dimeric	Chain D 308–705（398 aa）	Mutation：S654A	No recorded non-water small molecule	X-RAY DIFFRACTION X-ray crystallization conditions VAPOR DIFFUSION, HANGING DROP；293 K；0.2 M ammonium citrate tribasic (pH 7.0), 20% (w/v) PEG-3350	Resolution 3.10 Å R-free 0.278

11 other PDB entries and 14 assemblies. Open the comparison page and filter oligomeric states

View Construct and Data Evidence

UniProt name	C1R_HUMAN
Isoform	—
PDB entities	1
Chains and sequence ranges	Author chain A； PDBConstruct 1–291； UniProt 18–308 Author chain C； PDBConstruct 1–291； UniProt 18–308

Complement C1s subcomponent

Homo sapiens

UniProt P09871

State in the Current Structure

Assembly	Oligomeric State	Construct	Mutations and Modifications	Ligands, Ions and Associated Components	Method and Experimental Conditions	Structure Quality
1	Other combination Heteromer Protein × 2 其他Polymer 2 PDB declaration: dimeric（2） Consistent with protein copy count	Chain B； UniProt 17–292	Not recorded	Complement C1r subcomponent × 1 （P00736） ;2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-beta-D-galactopyranose-(1-4)-alpha-D-mannopyranose-(1-3)-[alpha-D-mannopyranose-(1-6)]beta-D-mannopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose ; × 1 beta-D-mannopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose × 1 CA CALCIUM ION × 6 NA SODIUM ION × 3 NAG 2-acetamido-2-deoxy-beta-D-glucopyranose × 1	X-RAY DIFFRACTION X-ray crystallization conditions：VAPOR DIFFUSION, SITTING DROP；pH 8；298 K；12-18% PEG 8000, 100 mM Imidazole at pH 8.0	Resolution 4.50 Å R-free 0.340
2	Other combination Heteromer Protein × 2 其他Polymer 3 PDB declaration: dimeric（2） Consistent with protein copy count	Chain D； UniProt 17–292	Not recorded	Complement C1r subcomponent × 1 （P00736） ;beta-D-galactopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-2)-alpha-D-mannopyranose-(1-3)-[alpha-D-mannopyranose-(1-6)]beta-D-mannopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose ; × 1 beta-D-mannopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose × 2 CA CALCIUM ION × 6 NA SODIUM ION × 3 LYS LYSINE × 1	X-RAY DIFFRACTION X-ray crystallization conditions：VAPOR DIFFUSION, SITTING DROP；pH 8；298 K；12-18% PEG 8000, 100 mM Imidazole at pH 8.0	Resolution 4.50 Å R-free 0.340

Other States of the Same Protein in the Database

Other PDB	Difference from Current Entry 6F1H	Assembly / Oligomeric State	Construct	Mutations and Modifications	Ligands, Ions and Non-polymers	Method and Experimental Conditions	Structure Quality
1ELV CRYSTAL STRUCTURE OF THE CATALYTIC DOMAIN OF HUMAN COMPLEMENT C1S PROTEASE Deposited 2000-03-14	Different construct Different mutation/modification Different oligomeric state Different ligand/ion Different experimental conditions Different structure-quality metrics	Assembly 1 Other combination Monomer；Protein × 1 PDB declaration: monomeric	Chain A 358–688（331 aa） Fragment：CCP2-SP CATALYTIC FRAGMENT: ASP363-ASP-673 SEGMENT PRECEDED BY AN ASP-LEU SEQUENCE ADDED AT THE N-TERMINAL END	Mutation：YES	SO4 SULFATE ION × 2 NES 2-(2-HYDROXY-1,1-DIHYDROXYMETHYL-ETHYLAMINO)-ETHANESULFONIC ACID × 1	X-RAY DIFFRACTION X-ray crystallization conditions VAPOR DIFFUSION, HANGING DROP；pH 7.4；277 K；PEG 4K 34%, AMMONIUM SULFATE 100mM, pH 7.4, VAPOR DIFFUSION, HANGING DROP, temperature 277K	Resolution 1.70 Å R-free 0.219
1NZI Crystal Structure of the CUB1-EGF Interaction Domain of Complement Protease C1s Deposited 2003-02-18	Different construct Different mutation/modification Different oligomeric state Different ligand/ion Different experimental conditions Different structure-quality metrics	Assembly 1 Protein homooligomer Homooligomer；Protein × 2 PDB declaration: dimeric	Chain A 16–174（159 aa） Fragment：CALCIUM-DEPENDENT INTERACTION DOMAIN Chain B 16–174（159 aa） Fragment：CALCIUM-DEPENDENT INTERACTION DOMAIN	Not recorded	CA CALCIUM ION × 2 MG MAGNESIUM ION × 2	X-RAY DIFFRACTION X-ray crystallization conditions VAPOR DIFFUSION, HANGING DROP；pH 7.5；293 K；PEG 4000, magnesium chloride, glycerol, pH 7.5, VAPOR DIFFUSION, HANGING DROP, temperature 293K	Resolution 1.50 Å R-free 0.234
4J1Y The X-ray crystal structure of human complement protease C1s zymogen Deposited 2013-02-03	Different construct Different mutation/modification Different oligomeric state Different ligand/ion Different experimental conditions Different structure-quality metrics	Assembly 1 Protein monomer Monomer；Protein × 1 PDB declaration: monomeric	Chain A 292–688（397 aa） Fragment：CCP1-CCP2-SPz (UNP Residues 292-698)	Mutation：Q436A, I438A	No recorded non-water small molecule	X-RAY DIFFRACTION X-ray crystallization conditions VAPOR DIFFUSION, HANGING DROP；pH 7.4；293 K；18% PEG 3350, 0.2M potassium nitrate., pH 7.4, VAPOR DIFFUSION, HANGING DROP, temperature 293K	Resolution 2.66 Å R-free 0.259
4J1Y The X-ray crystal structure of human complement protease C1s zymogen Deposited 2013-02-03	Different construct Different mutation/modification Different oligomeric state Different ligand/ion Different experimental conditions Different structure-quality metrics	Assembly 2 Protein monomer Monomer；Protein × 1 PDB declaration: monomeric	Chain B 292–688（397 aa） Fragment：CCP1-CCP2-SPz (UNP Residues 292-698)	Mutation：Q436A, I438A	No recorded non-water small molecule	X-RAY DIFFRACTION X-ray crystallization conditions VAPOR DIFFUSION, HANGING DROP；pH 7.4；293 K；18% PEG 3350, 0.2M potassium nitrate., pH 7.4, VAPOR DIFFUSION, HANGING DROP, temperature 293K	Resolution 2.66 Å R-free 0.259
4J1Y The X-ray crystal structure of human complement protease C1s zymogen Deposited 2013-02-03	Different construct Different mutation/modification Different oligomeric state Different ligand/ion Different experimental conditions Different structure-quality metrics	Assembly 3 Protein homooligomer Homooligomer；Protein × 2 PDB declaration: dimeric	Chain A 292–688（397 aa） Fragment：CCP1-CCP2-SPz (UNP Residues 292-698) Chain B 292–688（397 aa） Fragment：CCP1-CCP2-SPz (UNP Residues 292-698)	Mutation：Q436A, I438A Mutation：Q436A, I438A	No recorded non-water small molecule	X-RAY DIFFRACTION X-ray crystallization conditions VAPOR DIFFUSION, HANGING DROP；pH 7.4；293 K；18% PEG 3350, 0.2M potassium nitrate., pH 7.4, VAPOR DIFFUSION, HANGING DROP, temperature 293K	Resolution 2.66 Å R-free 0.259
4LMF C1s CUB1-EGF-CUB2 Deposited 2013-07-10	Different construct Different oligomeric state Different ligand/ion Different experimental conditions Different structure-quality metrics	Assembly 1 Protein monomer Monomer；Protein × 1 PDB declaration: monomeric	Chain A 17–292（276 aa） Fragment：CUB1-EGF-CUB2 fragment (unp residues 17-292)	Not recorded	NA SODIUM ION × 1 CA CALCIUM ION × 3	X-RAY DIFFRACTION X-ray crystallization conditions VAPOR DIFFUSION, SITTING DROP；pH 8.5；298 K；pH 8.5, VAPOR DIFFUSION, SITTING DROP, temperature 298K	Resolution 2.92 Å R-free 0.252
4LMF C1s CUB1-EGF-CUB2 Deposited 2013-07-10	Different construct Different oligomeric state Different ligand/ion Different experimental conditions Different structure-quality metrics	Assembly 2 Protein monomer Monomer；Protein × 1 PDB declaration: monomeric	Chain B 17–292（276 aa） Fragment：CUB1-EGF-CUB2 fragment (unp residues 17-292)	Not recorded	NA SODIUM ION × 1 CA CALCIUM ION × 3	X-RAY DIFFRACTION X-ray crystallization conditions VAPOR DIFFUSION, SITTING DROP；pH 8.5；298 K；pH 8.5, VAPOR DIFFUSION, SITTING DROP, temperature 298K	Resolution 2.92 Å R-free 0.252
4LMF C1s CUB1-EGF-CUB2 Deposited 2013-07-10	Different construct Different oligomeric state Different ligand/ion Different experimental conditions Different structure-quality metrics	Assembly 3 Protein monomer Monomer；Protein × 1 PDB declaration: monomeric	Chain C 17–292（276 aa） Fragment：CUB1-EGF-CUB2 fragment (unp residues 17-292)	Not recorded	NA SODIUM ION × 1 CA CALCIUM ION × 3	X-RAY DIFFRACTION X-ray crystallization conditions VAPOR DIFFUSION, SITTING DROP；pH 8.5；298 K；pH 8.5, VAPOR DIFFUSION, SITTING DROP, temperature 298K	Resolution 2.92 Å R-free 0.252
4LMF C1s CUB1-EGF-CUB2 Deposited 2013-07-10	Different construct Different oligomeric state Different ligand/ion Different experimental conditions Different structure-quality metrics	Assembly 4 Protein monomer Monomer；Protein × 1 PDB declaration: monomeric	Chain D 17–292（276 aa） Fragment：CUB1-EGF-CUB2 fragment (unp residues 17-292)	Not recorded	NA SODIUM ION × 1 CA CALCIUM ION × 3	X-RAY DIFFRACTION X-ray crystallization conditions VAPOR DIFFUSION, SITTING DROP；pH 8.5；298 K；pH 8.5, VAPOR DIFFUSION, SITTING DROP, temperature 298K	Resolution 2.92 Å R-free 0.252
4LMF C1s CUB1-EGF-CUB2 Deposited 2013-07-10	Different construct Different mutation/modification Different oligomeric state Different ligand/ion Different experimental conditions Different structure-quality metrics	Assembly 5 Protein homooligomer Homooligomer；Protein × 2 PDB declaration: dimeric	Chain A 17–292（276 aa） Fragment：CUB1-EGF-CUB2 fragment (unp residues 17-292) Chain D 17–292（276 aa） Fragment：CUB1-EGF-CUB2 fragment (unp residues 17-292)	Not recorded	NA SODIUM ION × 2 CA CALCIUM ION × 6	X-RAY DIFFRACTION X-ray crystallization conditions VAPOR DIFFUSION, SITTING DROP；pH 8.5；298 K；pH 8.5, VAPOR DIFFUSION, SITTING DROP, temperature 298K	Resolution 2.92 Å R-free 0.252
4LMF C1s CUB1-EGF-CUB2 Deposited 2013-07-10	Different construct Different mutation/modification Different oligomeric state Different ligand/ion Different experimental conditions Different structure-quality metrics	Assembly 6 Protein homooligomer Homooligomer；Protein × 2 PDB declaration: dimeric	Chain B 17–292（276 aa） Fragment：CUB1-EGF-CUB2 fragment (unp residues 17-292) Chain C 17–292（276 aa） Fragment：CUB1-EGF-CUB2 fragment (unp residues 17-292)	Not recorded	NA SODIUM ION × 2 CA CALCIUM ION × 6	X-RAY DIFFRACTION X-ray crystallization conditions VAPOR DIFFUSION, SITTING DROP；pH 8.5；298 K；pH 8.5, VAPOR DIFFUSION, SITTING DROP, temperature 298K	Resolution 2.92 Å R-free 0.252
4LOR C1s CUB1-EGF-CUB2 in complex with a collagen-like peptide from C1q Deposited 2013-07-13	Different construct Different oligomeric state Different ligand/ion Different experimental conditions Different structure-quality metrics	Assembly 1 Protein heterocomplex Heteromer；Protein × 4 PDB declaration: tetrameric	Chain A 17–292（276 aa） Fragment：CUB1-EGF-CUB2 fragment (unp residues 17-292)	Not recorded	CA CALCIUM ION × 3 NA SODIUM ION × 2 NAG 2-acetamido-2-deoxy-beta-D-glucopyranose × 1	X-RAY DIFFRACTION X-ray crystallization conditions VAPOR DIFFUSION, SITTING DROP；pH 8.5；293 K；100 mM Tris, 100 mM NaBr, 24% PEG 3350 , pH 8.5, VAPOR DIFFUSION, SITTING DROP, temperature 293K	Resolution 2.50 Å R-free 0.252
4LOS C1s CUB2-CCP1 Deposited 2013-07-13	Different construct Different oligomeric state Different ligand/ion Different experimental conditions Different structure-quality metrics	Assembly 1 Protein monomer Monomer；Protein × 1 PDB declaration: monomeric	Chain A 172–358（187 aa） Fragment：CUB2-CCP1 fragment (unp residues 172-358)	Not recorded	CA CALCIUM ION × 1	X-RAY DIFFRACTION X-ray crystallization conditions VAPOR DIFFUSION, SITTING DROP；pH 8；293 K；100 mM Tris/acetate, 200 mM KH2PO4 + 20% PEG 10K , pH 8, VAPOR DIFFUSION, SITTING DROP, temperature 293K	Resolution 2.00 Å R-free 0.212
4LOT C1s CUB2-CCP1-CCP2 Deposited 2013-07-13	Different construct Different oligomeric state Different ligand/ion Different experimental conditions Different structure-quality metrics	Assembly 1 Protein monomer Monomer；Protein × 1 PDB declaration: monomeric	Chain A 175–423（249 aa） Fragment：CUB2-CCP1-CCP2 fragment (unp residues 175-423)	Not recorded	No recorded non-water small molecule	X-RAY DIFFRACTION X-ray crystallization conditions VAPOR DIFFUSION, SITTING DROP；pH 6.3；293 K；24% PEG 8K in Bis-tris propane-HCL, containing 200 mM potassium citrate, pH 6.3, VAPOR DIFFUSION, SITTING DROP, temperature 293K	Resolution 2.92 Å R-free 0.292
5UBM Crystal structure of human C1s in complex with inhibitor gigastasin Deposited 2016-12-20	Different construct Different mutation/modification Different oligomeric state Different ligand/ion Different experimental conditions Different structure-quality metrics	Assembly 1 Other combination Heteromer；Protein × 3 PDB declaration: trimeric	Chain A 437–688（252 aa） Chain B 285–436（152 aa）	Not recorded	No recorded non-water small molecule	X-RAY DIFFRACTION X-ray crystallization conditions VAPOR DIFFUSION, HANGING DROP；pH 5.5；277 K；0.1 M Bis-Tris, pH 5.5, 25 % PEG 3350	Resolution 2.50 Å R-free 0.222
6F1C C1rC1s complex Deposited 2017-11-21	Different construct Different mutation/modification Different oligomeric state Different ligand/ion Different experimental conditions Different structure-quality metrics	Assembly 1 Other combination Heteromer；Protein × 4 PDB declaration: tetrameric	Chain B 16–292（277 aa） Chain D 16–292（277 aa）	Not recorded	CA CALCIUM ION × 12 NA SODIUM ION × 6 NAG 2-acetamido-2-deoxy-beta-D-glucopyranose × 2	X-RAY DIFFRACTION X-ray crystallization conditions VAPOR DIFFUSION, SITTING DROP；pH 8；293 K；12-18% PEG 8000, 100 mM Imidazole at pH 8.0	Resolution 4.20 Å R-free 0.305
8GMN Crystal structure of human C1s in complex with inhibitor Deposited 2023-03-26	Different construct Different oligomeric state Different ligand/ion Different experimental conditions Different structure-quality metrics	Assembly 1 Protein monomer Monomer；Protein × 1 PDB declaration: monomeric	Chain A 358–688（331 aa）	Not recorded	ZWK [4-(1-aminophthalazin-6-yl)piperazin-1-yl](2-methylphenyl)methanone × 1	X-RAY DIFFRACTION X-ray crystallization conditions VAPOR DIFFUSION, SITTING DROP；pH 7.5；277 K；22% PEG 3350, 50-100 mM Ammonium Sulphate and 100 mM TRIS pH 7.5-8.0	Resolution 2.60 Å R-free 0.281
8GMN Crystal structure of human C1s in complex with inhibitor Deposited 2023-03-26	Different construct Different oligomeric state Different ligand/ion Different experimental conditions Different structure-quality metrics	Assembly 2 Protein monomer Monomer；Protein × 1 PDB declaration: monomeric	Chain B 358–688（331 aa）	Not recorded	ZWK [4-(1-aminophthalazin-6-yl)piperazin-1-yl](2-methylphenyl)methanone × 1 SO4 SULFATE ION × 1	X-RAY DIFFRACTION X-ray crystallization conditions VAPOR DIFFUSION, SITTING DROP；pH 7.5；277 K；22% PEG 3350, 50-100 mM Ammonium Sulphate and 100 mM TRIS pH 7.5-8.0	Resolution 2.60 Å R-free 0.281
8GMN Crystal structure of human C1s in complex with inhibitor Deposited 2023-03-26	Different construct Different oligomeric state Different ligand/ion Different experimental conditions Different structure-quality metrics	Assembly 3 Protein monomer Monomer；Protein × 1 PDB declaration: monomeric	Chain C 358–688（331 aa）	Not recorded	ZWK [4-(1-aminophthalazin-6-yl)piperazin-1-yl](2-methylphenyl)methanone × 1 SO4 SULFATE ION × 1	X-RAY DIFFRACTION X-ray crystallization conditions VAPOR DIFFUSION, SITTING DROP；pH 7.5；277 K；22% PEG 3350, 50-100 mM Ammonium Sulphate and 100 mM TRIS pH 7.5-8.0	Resolution 2.60 Å R-free 0.281
8GMN Crystal structure of human C1s in complex with inhibitor Deposited 2023-03-26	Different construct Different oligomeric state Different ligand/ion Different experimental conditions Different structure-quality metrics	Assembly 4 Protein monomer Monomer；Protein × 1 PDB declaration: monomeric	Chain D 358–688（331 aa）	Not recorded	ZWK [4-(1-aminophthalazin-6-yl)piperazin-1-yl](2-methylphenyl)methanone × 1	X-RAY DIFFRACTION X-ray crystallization conditions VAPOR DIFFUSION, SITTING DROP；pH 7.5；277 K；22% PEG 3350, 50-100 mM Ammonium Sulphate and 100 mM TRIS pH 7.5-8.0	Resolution 2.60 Å R-free 0.281
8TYP Complement Protease C1s Inhibited by 6-(4-phenylpiperazin-1-yl)pyridine-3-carboximidamide Deposited 2023-08-25	Different construct Different oligomeric state Different ligand/ion Different experimental conditions Different structure-quality metrics	Assembly 1 Other combination Monomer；Protein × 1 PDB declaration: monomeric	Chain A 358–688（331 aa）	Not recorded	SQT 6-(4-phenylpiperazin-1-yl)pyridine-3-carboximidamide × 1	X-RAY DIFFRACTION X-ray crystallization conditions VAPOR DIFFUSION, HANGING DROP；293 K；0.2 M sodium acetate 0.1 M Tris-HCl (pH 8.1) PEG-4000 24% (w/v)	Resolution 1.80 Å R-free 0.196
8W18 The crystal structure of the Michaelis-Menten complex of a C1s/C1-INH at 3.94 Angstroms Deposited 2024-02-15	Different construct Different mutation/modification Different oligomeric state Different ligand/ion Different experimental conditions Different structure-quality metrics	Assembly 1 Protein heterocomplex Heteromer；Protein × 3 PDB declaration: trimeric	Chain A 292–437（146 aa） Fragment：Sushi domains Chain B 438–688（251 aa）	Mutation：S632A	No recorded non-water small molecule	X-RAY DIFFRACTION X-ray crystallization conditions VAPOR DIFFUSION, HANGING DROP；295 K；0.1 M L-Proline, 0.1M HEPES (pH 6.5), and 12% PEG 3,350	Resolution 3.94 Å R-free 0.281
9X1H Cryo-EM Structure of human complement C1s CUB domain in complex with RAY121 Deposited 2025-10-02	Different construct Different mutation/modification Different oligomeric state Different ligand/ion Different experimental method Different experimental conditions Different structure-quality metrics	Assembly 1 Protein heterocomplex Heteromer；Protein × 6 PDB declaration: hexameric	Chain A 16–292（277 aa） Chain B 16–292（277 aa）	Not recorded	CA CALCIUM ION × 4	ELECTRON MICROSCOPY cryo-EM buffer pH 7.5；20mM HEPES(7.5), 150mM NaCl, 3mM CaCl2, 0.03% DDM cryo-EM vitrification conditions Cryogen ETHANE	Resolution 2.60 Å

13 other PDB entries and 23 assemblies. Open the comparison page and filter oligomeric states

View Construct and Data Evidence

UniProt name	C1S_HUMAN
Isoform	—
PDB entities	2
Chains and sequence ranges	Author chain B； PDBConstruct 1–276； UniProt 17–292 Author chain D； PDBConstruct 1–276； UniProt 17–292

The page prioritizes protein identity, the current assembly, associated components, oligomeric state and cross-PDB links. Chain mapping and sequence ranges are retained as data evidence. Internal IDs, import timestamps and assembly operation expressions are maintenance fields and are not shown here.

SAXS scattering curve SAXS Profile

P(r) Distance Distribution P(r) Distribution

Download Download SAXS (.dat) P(r) (.pr.out) CIF

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2. Structure Basics 2. Structure Basics

Entry ID entry_id	6f1h
Deposition date deposition_date	2017-11-22
Structure title title	C1rC1s complex
Keywords keywords	CUB domain, EGF-like domain, complement, C1r-C1s, HYDROLASE; HYDROLASE
Experimental Method method	X-RAY DIFFRACTION

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3. SAXS Parameters (CRYSOL theoretical calculation) 3. SAXS Parameters (CRYSOL)

Radius of gyration Rg (Guinier) rg_guinier	44.64 Å
Radius of gyration Rg (electron density) rg_electron	44.68 Å
Forward intensity I(0) i0	270978000.00
Molecular weight molecular_weight	132770.0 kDa
Excluded volume excluded_volume	164650 Å³
Envelope volume envelope_volume	243920 Å³
Hydration-shell volume shell_volume	46967 Å³
Envelope diameter envelope_diameter	163.9 Å
Shell Rg shell_rg	46.77 Å
Envelope Rg envelope_rg	44.22 Å
Shape Rg shape_rg	44.67 Å
Total Rg total_rg	44.84 Å
Total atoms total_atoms	9318
Residues n_residues	1128
Spherical-harmonic order n_harmonics	20
q range q_range	— – 0.5000 Å⁻¹
Data points n_points	101
Shell type shell_type	directional
Solvent electron density solvent_density	0.3340 e/Å³
Shell contrast contrast_shell	0.0300 e/Å³
CRYSOL version crysol_version	4.1.3

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4. P(r) Distance Distribution (GNOM inversion) 4. P(r) Analysis (GNOM)

Maximum dimension Dmax dmax	155.2 Å
Rg (real space) rg_real	44.80 Å
Rg uncertainty (real space) rg_real_error	1.65 Å
I(0) (real space) i0_real	2.7100e+08
I(0) uncertainty (real space) i0_real_error	5.3220e+06
Rg (reciprocal space) rg_reciprocal	44.64 Å
I(0) (reciprocal space) i0_reciprocal	270900000.0000
Solution quality estimate total_estimate	0.8552
Solution quality rating solution_quality	GOOD a GOOD solution
P(r) peaks n_peaks	1
Primary peak position r_peak_primary	57.6 Å
Skewness Skewness skewness	0.351
Kurtosis Kurtosis kurtosis	-0.355
Angular range angular_range	— – 0.1750 Å⁻¹
Current regularization parameter α current_alpha	0.0000
Highest regularization parameter α highest_alpha	17940000.0000
Real-space data points n_real_points	36
GNOM version gnom_version	4.1.3
Quality Criteria quality_criteria	AN1: 0.000; Oscil: 0.856; Stabil: 1.000; Sysdev: 1.000; Positv: 1.000; Valcen: 0.859; Smooth: 0.686

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5. Crystallography and Experiment 5. Crystallography & Experiment

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6. Entities and Polymers Entities & Polymers (9)

Entity 1 Entity 1 polymer

Description description	Complement C1r subcomponent
Molecular weight formula_weight	33121.0 kDa
EC 编号 ec_number	3.4.21.41
Source method src_method	man
Copy count entity_count	2

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	A,C
Atom count atom_count	9318

SIPIPQKLFGEVTSPLFPKPYPNNFETTTVITVPTGYRVKLVFQQFDLEPSEGCFYDYVKISADKKSLGRFCGQLGSPLGNPPGKKEFMSQGNKMLLTFHTDFSNEENGTIMFYKGFLAYYQAVDLDECASRSKSGEEDPQPQCQHLCHNYVGGYFCSCRPGYELQEDTHSCQAECSSELYTEASGYISSLEYPRSYPPDLRCNYSIRVERGLTLHLKFLEPFDIDDHQQVHCPYDQLQIYANGKNIGEFCGKQRPPDLDTSSNAVDLLFFTDESGDSRGWKLRYTTEIIK

来源 Source

来源生物 organism	Homo sapiens
通用名 common_name	Human
NCBI Class编号 ncbi_taxonomy_id	9606
宿主生物 host_organism	Cricetulus griseus

Entity 2 Entity 2 polymer

Description description	Complement C1s subcomponent
Molecular weight formula_weight	31115.5 kDa
EC 编号 ec_number	3.4.21.42
Source method src_method	man
Copy count entity_count	2

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	D,B

PTMYGEILSPNYPQAYPSEVEKSWDIEVPEGYGIHLYFTHLDIELSENCAYDSVQIISGDTEEGRLCGQRSSNNPHSPIVEEFQVPYNKLQVIFKSDFSNEERFTGFAAYYVATDINECTDFVDVPCSHFCNNFIGGYFCSCPPEYFLHDDMKNCGVNCSGDVFTALIGEIASPNYPKPYPENSRCEYQIRLEKGFQVVVTLRREDFDVEAADSAGNCLDSLVFVAGDRQFGPYCGHGFPGPLNIETKSNALDIIFQTDLTGQKKGWKLRYHGDPM

来源 Source

来源生物 organism	Homo sapiens
通用名 common_name	Human
NCBI Class编号 ncbi_taxonomy_id	9606
宿主生物 host_organism	Cricetulus griseus

Entity 3 Entity 3 branched

Description description	;2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-beta-D-galactopyranose-(1-4)-alpha-D-mannopyranose-(1-3)-[alpha-D-mannopyranose-(1-6)]beta-D-mannopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose ;
Molecular weight formula_weight	1276.2 kDa
Source method src_method	man
Copy count entity_count	1

Entity 4 Entity 4 branched

Description description	;beta-D-galactopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-2)-alpha-D-mannopyranose-(1-3)-[alpha-D-mannopyranose-(1-6)]beta-D-mannopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose ;
Molecular weight formula_weight	1276.2 kDa
Source method src_method	man
Copy count entity_count	1

Entity 5 Entity 5 branched

Description description	beta-D-mannopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose
Molecular weight formula_weight	586.5 kDa
Source method src_method	man
Copy count entity_count	3

Entity 6 Entity 6 non-polymer

Description description	CALCIUM ION
Molecular weight formula_weight	40.1 kDa
Source method src_method	syn
Copy count entity_count	12

Entity 7 Entity 7 non-polymer

Description description	SODIUM ION
Molecular weight formula_weight	23.0 kDa
Source method src_method	syn
Copy count entity_count	6

Entity 8 Entity 8 non-polymer

Description description	2-acetamido-2-deoxy-beta-D-glucopyranose
Molecular weight formula_weight	221.2 kDa
Source method src_method	man
Copy count entity_count	1

Entity 9 Entity 9 non-polymer

Description description	LYSINE
Molecular weight formula_weight	147.2 kDa
Source method src_method	syn
Copy count entity_count	1

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8. Citations (1)

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Unit-cell length a length_a	88.209 Å
Unit-cell length b length_b	88.340 Å
Unit-cell length c length_c	197.559 Å
Unit-cell angle α angle_alpha	90.00 °
Unit-cell angle β angle_beta	90.00 °
Unit-cell angle γ angle_gamma	90.00 °
Molecules per unit cell Z z_pdb	8

Space group space_group	P 21 21 21
Space-group number int_tables_number	19
Crystal system crystal_system	—

Resolution resolution	4.500 Å
Low-resolution limit resolution_low	80.645 Å
R factor r_factor	0.3052
R_work r_work	0.3035
R_free r_free	0.3398

fit	/app/data/saxs_computation/f1/6f1h/6f1h.fit
pddf	/app/data/pr_computation/f1/6f1h/6f1h.pr.out
profile	/app/data/saxs_computation/f1/6f1h/6f1h.dat

C1rC1s complex

1. Protein Identity and Related Structures Protein Identity & Related Structures

Complement C1r subcomponent

State in the Current Structure

Other States of the Same Protein in the Database

Complement C1s subcomponent

State in the Current Structure

Other States of the Same Protein in the Database

SAXS scattering curve SAXS Profile

P(r) Distance Distribution P(r) Distribution

2. Structure Basics 2. Structure Basics

3. SAXS Parameters (CRYSOL theoretical calculation) 3. SAXS Parameters (CRYSOL)

4. P(r) Distance Distribution (GNOM inversion) 4. P(r) Analysis (GNOM)

5. Crystallography and Experiment 5. Crystallography & Experiment

Unit cell Unit Cell

Symmetry Symmetry

Refinement Refinement

Diffraction experiment Diffraction

6. Entities and Polymers Entities & Polymers (9)

Entity 1 Entity 1 polymer

Polymer Polymer

来源 Source

Entity 2 Entity 2 polymer

Polymer Polymer

来源 Source

Entity 3 Entity 3 branched

Entity 4 Entity 4 branched

Entity 5 Entity 5 branched

Entity 6 Entity 6 non-polymer

Entity 7 Entity 7 non-polymer

Entity 8 Entity 8 non-polymer

Entity 9 Entity 9 non-polymer

8. Citations (1)

9. Files and Curves (10)

Files (7)

Curves (3)