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Protein Structures and Oligomeric States

Enter a protein name, UniProt accession or PDB ID. Name searches ask you to confirm the protein identity before related structures are queried.

Current Protein Identity：P02746 New Search
11PDB entries
16Biological assembly
26chain/assembly records
Main Difference Dimensions in This Set
Different construct Different mutation/modification Different assembly state Different ligand/ion Different experimental method Different experimental conditions Different structure-quality metrics

Difference tags compare only the current result set; every original PDB and assembly record remains separate.

Related-Structure Differences

Each row represents one biological assembly in one PDB entry; multiple monomers of the same protein are listed separately.

PDB Entry Assembly / Oligomeric State Construct Mutations and Modifications Ligands, Ions and Non-polymers Experimental Method Experimental Conditions Structure Quality
1PK6 Globular Head of the Complement System Protein C1q Deposited 2003-06-05 Assembly 1 Protein heterocomplex Heteromer；Protein × 3 PDB declaration: trimeric（3） Consistent with protein count
Chain B 117–248（132 aa）
Not recorded CA CALCIUM ION × 1 X-RAY DIFFRACTION
X-ray crystallization conditions VAPOR DIFFUSION, HANGING DROP；pH 7；293 K；PEG 4000, CaCl2, B-mercaptoethanol, agarose, pH 7.0, VAPOR DIFFUSION, HANGING DROP, temperature 20K
Resolution 1.85 Å R-free 0.239
2JG8 Crystallographic structure of human C1q globular heads complexed to phosphatidyl-serine Deposited 2007-02-09 Assembly 1 Protein heterocomplex Heteromer；Protein × 3 PDB declaration: trimeric（3） Consistent with protein count
Chain B 118–253（136 aa） Fragment：C TERMINAL GLOBULAR DOMAIN, RESIDUES 116-251
Not recorded NAG 2-acetamido-2-deoxy-beta-D-glucopyranose × 1 CA CALCIUM ION × 1 X-RAY DIFFRACTION mmCIF provides none of the parsed conditions Resolution 2.05 Å R-free 0.241
2JG8 Crystallographic structure of human C1q globular heads complexed to phosphatidyl-serine Deposited 2007-02-09 Assembly 2 Protein heterocomplex Heteromer；Protein × 3 PDB declaration: trimeric（3） Consistent with protein count
Chain E 118–253（136 aa） Fragment：C TERMINAL GLOBULAR DOMAIN, RESIDUES 116-251
Not recorded CA CALCIUM ION × 1 SEP PHOSPHOSERINE × 1 X-RAY DIFFRACTION mmCIF provides none of the parsed conditions Resolution 2.05 Å R-free 0.241
2JG9 Crystallographic structure of human C1q globular heads (P1) Deposited 2007-02-09 Assembly 1 Protein heterocomplex Heteromer；Protein × 3 PDB declaration: trimeric（3） Consistent with protein count
Chain B 118–253（136 aa） Fragment：C TERMINAL GLOBULAR DOMAIN, RESIDUES 116-251
Not recorded CA CALCIUM ION × 1 X-RAY DIFFRACTION mmCIF provides none of the parsed conditions Resolution 1.90 Å R-free 0.260
2JG9 Crystallographic structure of human C1q globular heads (P1) Deposited 2007-02-09 Assembly 2 Protein heterocomplex Heteromer；Protein × 3 PDB declaration: trimeric（3） Consistent with protein count
Chain E 118–253（136 aa） Fragment：C TERMINAL GLOBULAR DOMAIN, RESIDUES 116-251
Not recorded CA CALCIUM ION × 1 X-RAY DIFFRACTION mmCIF provides none of the parsed conditions Resolution 1.90 Å R-free 0.260
2WNU Complex between c1q globular heads and heparan sulfate Deposited 2009-07-20 Assembly 1 Other combination Heteromer；Protein × 3 PDB declaration: trimeric（3） Consistent with protein count
Chain E 116–251（136 aa） Fragment：C TERMINAL GLOBULAR DOMAIN, RESIDUES 116-251
Not recorded No recorded non-water small molecule X-RAY DIFFRACTION mmCIF provides none of the parsed conditions Resolution 2.30 Å R-free 0.256
2WNU Complex between c1q globular heads and heparan sulfate Deposited 2009-07-20 Assembly 2 Protein heterocomplex Heteromer；Protein × 3 PDB declaration: trimeric（3） Consistent with protein count
Chain B 116–251（136 aa） Fragment：C TERMINAL GLOBULAR DOMAIN, RESIDUES 116-251
Not recorded NAG 2-acetamido-2-deoxy-beta-D-glucopyranose × 1 X-RAY DIFFRACTION mmCIF provides none of the parsed conditions Resolution 2.30 Å R-free 0.256
2WNV Complex between C1q globular heads and deoxyribose Deposited 2009-07-20 Assembly 1 Protein heterocomplex Heteromer；Protein × 3 PDB declaration: trimeric（3） Consistent with protein count
Chain B 116–251（136 aa） Fragment：C TERMINAL GLOBULAR DOMAIN, RESIDUES 116-251
Not recorded NAG 2-acetamido-2-deoxy-beta-D-glucopyranose × 1 CA CALCIUM ION × 1 2DR 2-deoxy-beta-D-erythro-pentofuranose × 1 X-RAY DIFFRACTION mmCIF provides none of the parsed conditions Resolution 1.25 Å R-free 0.202
2WNV Complex between C1q globular heads and deoxyribose Deposited 2009-07-20 Assembly 2 Protein heterocomplex Heteromer；Protein × 3 PDB declaration: trimeric（3） Consistent with protein count
Chain E 116–251（136 aa） Fragment：C TERMINAL GLOBULAR DOMAIN, RESIDUES 116-251
Not recorded NAG 2-acetamido-2-deoxy-beta-D-glucopyranose × 1 CA CALCIUM ION × 1 X-RAY DIFFRACTION mmCIF provides none of the parsed conditions Resolution 1.25 Å R-free 0.202
5HKJ Single Chain Recombinant Globular Head of the Complement System Protein C1q Deposited 2016-01-14 Assembly 1 Insufficient information Monomer；Protein × 1 PDB declaration: monomeric（1） Consistent with protein count
Chain A 117–253（137 aa）
Not recorded NAG 2-acetamido-2-deoxy-beta-D-glucopyranose × 1 CA CALCIUM ION × 1 X-RAY DIFFRACTION
X-ray crystallization conditions VAPOR DIFFUSION, HANGING DROP；pH 8.5；293 K；23% PEG 3350, 0.1 M Tris, 0.2 M NaCl, 50 mM CaCl2
Resolution 1.35 Å R-free 0.200
5HZF Single Chain Recombinant Globular Head of the Complement System Protein C1q in complex with magnesium Deposited 2016-02-02 Assembly 1 Insufficient information Monomer；Protein × 1 PDB declaration: monomeric（1） Consistent with protein count
Chain A 117–253（137 aa）
Not recorded MG MAGNESIUM ION × 1 X-RAY DIFFRACTION
X-ray crystallization conditions VAPOR DIFFUSION, HANGING DROP；pH 7.5；293 K；30% PEG 8000, 0.1M HEPES, pH 7.5
Resolution 1.55 Å R-free 0.186
6FCZ Model of gC1q-Fc complex based on 7A EM map Deposited 2017-12-21 Assembly 1 Protein heterocomplex Heteromer；Protein × 5 PDB declaration: pentameric（5） Consistent with protein count
Chain B 119–250（132 aa） Fragment：UNP Residues 119-250
Not recorded No recorded non-water small molecule ELECTRON MICROSCOPY
cryo-EM buffer pH 7.5
cryo-EM vitrification conditions Cryogen ETHANE
Resolution 10.00 Å
6Z6V Globular head of C1q in complex with the nanobody C1qNb75 Deposited 2020-05-29 Assembly 1 Protein heterocomplex Heteromer；Protein × 4 PDB declaration: tetrameric（4） Consistent with protein count
Chain B 119–253（135 aa）
Not recorded NAG 2-acetamido-2-deoxy-beta-D-glucopyranose × 1 X-RAY DIFFRACTION
X-ray crystallization conditions VAPOR DIFFUSION, SITTING DROP；pH 5.5；292 K；0.1 M BIS-Tris pH 5.5, 25 % w/v PEG 3350
Resolution 2.19 Å R-free 0.227
6Z6V Globular head of C1q in complex with the nanobody C1qNb75 Deposited 2020-05-29 Assembly 2 Protein heterocomplex Heteromer；Protein × 4 PDB declaration: tetrameric（4） Consistent with protein count
Chain E 119–253（135 aa）
Not recorded NAG 2-acetamido-2-deoxy-beta-D-glucopyranose × 1 X-RAY DIFFRACTION
X-ray crystallization conditions VAPOR DIFFUSION, SITTING DROP；pH 5.5；292 K；0.1 M BIS-Tris pH 5.5, 25 % w/v PEG 3350
Resolution 2.19 Å R-free 0.227
9C9L Cryo-EM structure of the C1q A, B-crt, C peptide assembly narrow region Deposited 2024-06-14 Assembly 1 Protein heterocomplex Heteromer；Protein × 18 PDB declaration: octadecameric（18） Consistent with protein count
Chain A 34–46（13 aa）
Chain D 34–46（13 aa）
Chain E 34–46（13 aa）
Chain F 34–46（13 aa）
Chain G 34–46（13 aa）
Chain H 34–46（13 aa）
Non-standard monomer：Yes (specific site not provided by mmCIF) Non-standard monomer：Yes (specific site not provided by mmCIF) Non-standard monomer：Yes (specific site not provided by mmCIF) Non-standard monomer：Yes (specific site not provided by mmCIF) Non-standard monomer：Yes (specific site not provided by mmCIF) Non-standard monomer：Yes (specific site not provided by mmCIF) No recorded non-water small molecule ELECTRON MICROSCOPY
cryo-EM buffer pH 7.4；20 mM PBS
cryo-EM vitrification conditions Cryogen ETHANE
Resolution 3.70 Å
9C9U Cryo-EM structure of the C1q A, B-crt, C peptide full assembly Deposited 2024-06-15 Assembly 1 Protein heterocomplex Heteromer；Protein × 18 PDB declaration: 18-meric（18） Consistent with protein count
Chain A 28–71（44 aa）
Chain D 28–71（44 aa）
Chain E 28–71（44 aa）
Chain F 28–71（44 aa）
Chain G 28–71（44 aa）
Chain H 28–71（44 aa）
Non-standard monomer：Yes (specific site not provided by mmCIF) Non-standard monomer：Yes (specific site not provided by mmCIF) Non-standard monomer：Yes (specific site not provided by mmCIF) Non-standard monomer：Yes (specific site not provided by mmCIF) Non-standard monomer：Yes (specific site not provided by mmCIF) Non-standard monomer：Yes (specific site not provided by mmCIF) No recorded non-water small molecule ELECTRON MICROSCOPY
cryo-EM buffer pH 7.4
cryo-EM vitrification conditions Cryogen ETHANE
Resolution 4.50 Å

This page presents structural evidence recorded in PDB/mmCIF.“No recorded non-water small molecule” does not prove that the experimental sample was ligand-free; experimental conditions belong to the PDB experiment, while ligands and copy counts are shown for each biological assembly.