1ow0

Crystal structure of human FcaRI bound to IgA1-Fc

Method: X-RAY DIFFRACTION D_max: 111.4 Å Quality: REASONABLE

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

Ig alpha-1 chain C region

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 Homooligomer Protein × 2 其他Polymer 2 PDB declaration: dimeric（2） Consistent with protein copy count	Chain A； UniProt 122–335 Chain B； UniProt 122–335	Fragment：Fc region	;N-acetyl-alpha-neuraminic acid-(2-3)-beta-D-galactopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-2)-beta-D-mannopyranose-(1-6)-beta-D-mannopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-[beta-L-fucopyranose-(1-6)]2-acetamido-2-deoxy-beta-D-glucopyranose ; × 1 ;N-acetyl-alpha-neuraminic acid-(2-3)-beta-D-galactopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-2)-beta-D-mannopyranose-(1-6)-beta-D-mannopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-[alpha-L-fucopyranose-(1-6)]2-acetamido-2-deoxy-beta-D-glucopyranose ; × 1	X-RAY DIFFRACTION X-ray crystallization conditions：VAPOR DIFFUSION, HANGING DROP；pH 6.5；296 K；magnesium sulfate heptahydrate, MES, pH 6.5, VAPOR DIFFUSION, HANGING DROP, temperature 296K	Resolution 3.10 Å R-free 0.284
4	Other combination Heteromer Protein × 4 其他Polymer 8 PDB declaration: tetrameric（4） Consistent with protein copy count	Chain A； UniProt 122–335 Chain B； UniProt 122–335	Fragment：Fc region	Immunoglobulin alpha Fc receptor × 2 （P24071） ;N-acetyl-alpha-neuraminic acid-(2-3)-beta-D-galactopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-2)-beta-D-mannopyranose-(1-6)-beta-D-mannopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-[beta-L-fucopyranose-(1-6)]2-acetamido-2-deoxy-beta-D-glucopyranose ; × 1 ;N-acetyl-alpha-neuraminic acid-(2-3)-beta-D-galactopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-2)-beta-D-mannopyranose-(1-6)-beta-D-mannopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-[alpha-L-fucopyranose-(1-6)]2-acetamido-2-deoxy-beta-D-glucopyranose ; × 1 ;alpha-D-mannopyranose-(1-3)-[beta-D-mannopyranose-(1-6)]alpha-D-mannopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose ; × 2 beta-D-mannopyranose-(1-4)-2-acetamido-2-deoxy-alpha-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose × 2 ;beta-D-mannopyranose-(1-4)-beta-D-mannopyranose-(1-2)-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 ; × 2 NAG 2-acetamido-2-deoxy-beta-D-glucopyranose × 2	X-RAY DIFFRACTION X-ray crystallization conditions：VAPOR DIFFUSION, HANGING DROP；pH 6.5；296 K；magnesium sulfate heptahydrate, MES, pH 6.5, VAPOR DIFFUSION, HANGING DROP, temperature 296K	Resolution 3.10 Å R-free 0.284

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 1OW0	Assembly / Oligomeric State	Construct	Mutations and Modifications	Ligands, Ions and Non-polymers	Method and Experimental Conditions	Structure Quality
1IGA MODEL OF HUMAN IGA1 DETERMINED BY SOLUTION SCATTERING CURVE-FITTING AND HOMOLOGY MODELLING Deposited 1998-12-23	Different construct Different oligomeric state Different experimental method Different experimental conditions Different structure-quality metrics	Assembly 1 Protein heterocomplex Heteromer；Protein × 4 PDB declaration: tetrameric	Chain A 1–353（353 aa） Fragment：CHAINS A AND B, HEAVY, CHAINS C AND D, LIGHT Chain B 1–353（353 aa） Fragment：CHAINS A AND B, HEAVY, CHAINS C AND D, LIGHT	Not recorded	No recorded non-water small molecule	SOLUTION SCATTERING mmCIF provides none of the parsed conditions	Resolution not provided
2QEJ Crystal structure of a Staphylococcus aureus protein (SSL7) in complex with Fc of human IgA1 Deposited 2007-06-26	Different construct Different oligomeric state Different ligand/ion Different experimental conditions Different structure-quality metrics	Assembly 1 Other combination Heteromer；Protein × 4 PDB declaration: pentameric	Chain A 123–336（214 aa） Fragment：FC REGION Chain B 123–336（214 aa） Fragment：FC REGION	Not recorded	GOL GLYCEROL × 5 CA CALCIUM ION × 1	X-RAY DIFFRACTION X-ray crystallization conditions VAPOR DIFFUSION；pH 6.5；291 K；12% PEG 8000, 66 mM sodium cacodylate pH 6.5, 130 mM calcium acetate, VAPOR DIFFUSION, temperature 291K	Resolution 3.20 Å R-free 0.312
2QTJ Solution structure of human dimeric immunoglobulin A Deposited 2007-08-02	Different construct Different oligomeric state Different experimental method Different experimental conditions Different structure-quality metrics	Assembly 1 Protein heterocomplex Heteromer；Protein × 4 PDB declaration: tetrameric	Chain A 1–475（475 aa） Chain B 1–475（475 aa）	Not recorded	No recorded non-water small molecule	SOLUTION SCATTERING mmCIF provides none of the parsed conditions	Resolution not provided
2QTJ Solution structure of human dimeric immunoglobulin A Deposited 2007-08-02	Different construct Different oligomeric state Different experimental method Different experimental conditions Different structure-quality metrics	Assembly 2 Protein heterocomplex Heteromer；Protein × 4 PDB declaration: tetrameric	Chain C 1–475（475 aa） Chain D 1–475（475 aa）	Not recorded	No recorded non-water small molecule	SOLUTION SCATTERING mmCIF provides none of the parsed conditions	Resolution not provided
3CHN Solution structure of human secretory IgA1 Deposited 2008-03-10	Different construct Different mutation/modification Different oligomeric state Different experimental method Different experimental conditions Different structure-quality metrics	Assembly 1 Protein heterocomplex Heteromer；Protein × 10 PDB declaration: decameric	Chain A 1–353（353 aa） Chain B 1–353（353 aa） Chain C 1–353（353 aa） Chain D 1–353（353 aa）	Not recorded	No recorded non-water small molecule	SOLUTION SCATTERING mmCIF provides none of the parsed conditions	Resolution not provided
6LX3 Cryo-EM structure of human secretory immunoglobulin A Deposited 2020-02-10	Different construct Different mutation/modification Different oligomeric state Different experimental method Different experimental conditions Different structure-quality metrics	Assembly 1 Insufficient information Heteromer；Protein × 6 PDB declaration: hexameric	Chain A 122–353（232 aa） Chain B 122–353（232 aa） Chain C 122–353（232 aa） Chain D 122–353（232 aa）	Not recorded	No recorded non-water small molecule	ELECTRON MICROSCOPY cryo-EM buffer pH 7.4 cryo-EM vitrification conditions Cryogen ETHANE	Resolution 3.15 Å
6LXW Cryo-EM structure of human secretory immunoglobulin A in complex with the N-terminal domain of SpsA Deposited 2020-02-12	Different construct Different mutation/modification Different oligomeric state Different experimental method Different experimental conditions Different structure-quality metrics	Assembly 1 Insufficient information Heteromer；Protein × 7 PDB declaration: heptameric	Chain A 122–353（232 aa） Chain B 122–353（232 aa） Chain C 122–353（232 aa） Chain D 122–353（232 aa）	Not recorded	No recorded non-water small molecule	ELECTRON MICROSCOPY cryo-EM buffer pH 7.4 cryo-EM vitrification conditions Cryogen ETHANE	Resolution 3.27 Å
6UE7 Structure of dimeric sIgA complex Deposited 2019-09-20	Different construct Different mutation/modification Different oligomeric state Different ligand/ion Different experimental method Different experimental conditions Different structure-quality metrics	Assembly 1 Other combination Heteromer；Protein × 6 PDB declaration: hexameric	Chain A 123–353（231 aa） Fragment：UNP residues 123-353 Chain B 123–353（231 aa） Fragment：UNP residues 123-353 Chain F 123–353（231 aa） Fragment：UNP residues 123-353 Chain G 123–353（231 aa） Fragment：UNP residues 123-353	Not recorded	NAG 2-acetamido-2-deoxy-beta-D-glucopyranose × 7	ELECTRON MICROSCOPY cryo-EM buffer pH 7.2 cryo-EM vitrification conditions Cryogen ETHANE	Resolution 2.90 Å
6XJA Streptococcus Pneumoniae IgA1 Protease with IgA1 substrate Deposited 2020-06-23	Different construct Different oligomeric state Different experimental method Different experimental conditions Different structure-quality metrics	Assembly 1 Protein heterocomplex Heteromer；Protein × 5 PDB declaration: pentameric	Chain A 122–331（210 aa） Chain B 122–331（210 aa）	Not recorded	No recorded non-water small molecule	ELECTRON MICROSCOPY cryo-EM buffer pH 7；20 mM Hepes, pH 7 150 mM NaCl cryo-EM vitrification conditions Cryogen ETHANE	Resolution 4.00 Å
7UVL IgA1 Protease with IgA1 substrate Deposited 2022-05-02	Different construct Different oligomeric state Different experimental method Different experimental conditions Different structure-quality metrics	Assembly 1 Protein heterocomplex Heteromer；Protein × 5 PDB declaration: pentameric	Chain A 123–331（209 aa） Chain B 123–331（209 aa）	Not recorded	No recorded non-water small molecule	ELECTRON MICROSCOPY cryo-EM buffer pH 7.4 cryo-EM vitrification conditions Cryogen ETHANE	Resolution 3.56 Å
8SKU Structure of human SIgA1 in complex with human CD89 (FcaR1) Deposited 2023-04-20	Different construct Different mutation/modification Different oligomeric state Different ligand/ion Different experimental method Different experimental conditions Different structure-quality metrics	Assembly 1 Other combination Heteromer；Protein × 8 PDB declaration: octameric	Chain A 1–353（353 aa） Chain B 1–353（353 aa） Chain C 1–353（353 aa） Chain D 1–353（353 aa）	Not recorded	NAG 2-acetamido-2-deoxy-beta-D-glucopyranose × 4	ELECTRON MICROSCOPY cryo-EM buffer pH 7 cryo-EM vitrification conditions Cryogen ETHANE	Resolution 3.20 Å
8SKV Structure of human SIgA1 in complex with Streptococcus pyogenes protein M4 (Arp4) Deposited 2023-04-20	Different construct Different mutation/modification Different oligomeric state Different ligand/ion Different experimental method Different experimental conditions Different structure-quality metrics	Assembly 1 Other combination Heteromer；Protein × 8 PDB declaration: octameric	Chain A 1–353（353 aa） Chain B 1–353（353 aa） Chain C 1–353（353 aa） Chain D 1–353（353 aa）	Not recorded	NAG 2-acetamido-2-deoxy-beta-D-glucopyranose × 7	ELECTRON MICROSCOPY cryo-EM buffer pH 7 cryo-EM vitrification conditions Cryogen ETHANE	Resolution 3.10 Å
9MBZ Cryo-EM structure of human FcRL4 bound to IgA-Fc/J Deposited 2025-03-17	Different construct Different mutation/modification Different oligomeric state Different experimental method Different experimental conditions Different structure-quality metrics	Assembly 1 Insufficient information Heteromer；Protein × 6 PDB declaration: hexameric	Chain A 122–353（232 aa） Chain B 122–353（232 aa） Chain C 122–353（232 aa） Chain D 122–353（232 aa）	Not recorded	No recorded non-water small molecule	ELECTRON MICROSCOPY mmCIF provides none of the parsed conditions	Resolution 3.30 Å
9OFR CRYSTAL STRUCTURE OF THE HUMAN IGA1 FC FRAGMENT-FC-ALPHA RECEPTOR (CD89) COMPLEX Deposited 2025-04-30	Different construct 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 123–335（213 aa） Fragment：FC fragment, UNP residues 123-335 Chain B 123–335（213 aa） Fragment：FC fragment, UNP residues 123-335	Not recorded	NAG 2-acetamido-2-deoxy-beta-D-glucopyranose × 7	X-RAY DIFFRACTION X-ray crystallization conditions VAPOR DIFFUSION, HANGING DROP；pH 8；294 K；0.15M sodium chloride 0.1M Tris-HCl pH 8.0 8% PEG 6000	Resolution 2.65 Å R-free 0.264
9OFR CRYSTAL STRUCTURE OF THE HUMAN IGA1 FC FRAGMENT-FC-ALPHA RECEPTOR (CD89) COMPLEX Deposited 2025-04-30	Different construct Different oligomeric state Different ligand/ion Different experimental conditions Different structure-quality metrics	Assembly 2 Protein heterocomplex Heteromer；Protein × 4 PDB declaration: tetrameric	Chain E 123–335（213 aa） Fragment：FC fragment, UNP residues 123-335 Chain G 123–335（213 aa） Fragment：FC fragment, UNP residues 123-335	Not recorded	NAG 2-acetamido-2-deoxy-beta-D-glucopyranose × 7	X-RAY DIFFRACTION X-ray crystallization conditions VAPOR DIFFUSION, HANGING DROP；pH 8；294 K；0.15M sodium chloride 0.1M Tris-HCl pH 8.0 8% PEG 6000	Resolution 2.65 Å R-free 0.264
9R2E Structure of ARGX-121 Fab fragment in complex with the Fc fragment of IgA1 Deposited 2025-04-30	Different construct Different oligomeric state Different ligand/ion Different experimental conditions Different structure-quality metrics	Assembly 1 Protein heterocomplex Heteromer；Protein × 6 PDB declaration: hexameric	Chain P 123–335（213 aa） Chain Q 123–335（213 aa）	Not recorded	EDO 1,2-ETHANEDIOL × 4 PEG DI(HYDROXYETHYL)ETHER × 5 MG MAGNESIUM ION × 3	X-RAY DIFFRACTION X-ray crystallization conditions VAPOR DIFFUSION, SITTING DROP；277 K；16% (w/v) PEG8000, 20% (v/v) Glycerol, 0.16 M MgAcetate, 0.08 M Na Cacodylate pH 6.50	Resolution 2.54 Å R-free 0.252

14 other PDB entries and 16 assemblies. Open the comparison page and filter oligomeric states

View Construct and Data Evidence

UniProt name	ALC1_HUMAN
Isoform	—
PDB entities	1
Chains and sequence ranges	Author chain A； PDBConstruct 1–214； UniProt 122–335 Author chain B； PDBConstruct 1–214； UniProt 122–335

Immunoglobulin alpha Fc receptor

Homo sapiens

UniProt P24071

State in the Current Structure

Assembly	Oligomeric State	Construct	Mutations and Modifications	Ligands, Ions and Associated Components	Method and Experimental Conditions	Structure Quality
2	Other combination Monomer Protein × 1 其他Polymer 3 PDB declaration: monomeric（1） Consistent with protein copy count	Chain C； UniProt 22–216	Fragment：ectodomain	;alpha-D-mannopyranose-(1-3)-[beta-D-mannopyranose-(1-6)]alpha-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-alpha-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose × 1 ;beta-D-mannopyranose-(1-4)-beta-D-mannopyranose-(1-2)-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 NAG 2-acetamido-2-deoxy-beta-D-glucopyranose × 1	X-RAY DIFFRACTION X-ray crystallization conditions：VAPOR DIFFUSION, HANGING DROP；pH 6.5；296 K；magnesium sulfate heptahydrate, MES, pH 6.5, VAPOR DIFFUSION, HANGING DROP, temperature 296K	Resolution 3.10 Å R-free 0.284
3	Other combination Monomer Protein × 1 其他Polymer 3 PDB declaration: monomeric（1） Consistent with protein copy count	Chain D； UniProt 22–216	Fragment：ectodomain	;alpha-D-mannopyranose-(1-3)-[beta-D-mannopyranose-(1-6)]alpha-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-alpha-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose × 1 ;beta-D-mannopyranose-(1-4)-beta-D-mannopyranose-(1-2)-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 NAG 2-acetamido-2-deoxy-beta-D-glucopyranose × 1	X-RAY DIFFRACTION X-ray crystallization conditions：VAPOR DIFFUSION, HANGING DROP；pH 6.5；296 K；magnesium sulfate heptahydrate, MES, pH 6.5, VAPOR DIFFUSION, HANGING DROP, temperature 296K	Resolution 3.10 Å R-free 0.284
4	Other combination Heteromer Protein × 4 其他Polymer 8 PDB declaration: tetrameric（4） Consistent with protein copy count	Chain C； UniProt 22–216 Chain D； UniProt 22–216	Fragment：ectodomain	Ig alpha-1 chain C region × 2 （P01876） ;N-acetyl-alpha-neuraminic acid-(2-3)-beta-D-galactopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-2)-beta-D-mannopyranose-(1-6)-beta-D-mannopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-[beta-L-fucopyranose-(1-6)]2-acetamido-2-deoxy-beta-D-glucopyranose ; × 1 ;N-acetyl-alpha-neuraminic acid-(2-3)-beta-D-galactopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-2)-beta-D-mannopyranose-(1-6)-beta-D-mannopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-[alpha-L-fucopyranose-(1-6)]2-acetamido-2-deoxy-beta-D-glucopyranose ; × 1 ;alpha-D-mannopyranose-(1-3)-[beta-D-mannopyranose-(1-6)]alpha-D-mannopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose ; × 2 beta-D-mannopyranose-(1-4)-2-acetamido-2-deoxy-alpha-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose × 2 ;beta-D-mannopyranose-(1-4)-beta-D-mannopyranose-(1-2)-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 ; × 2 NAG 2-acetamido-2-deoxy-beta-D-glucopyranose × 2	X-RAY DIFFRACTION X-ray crystallization conditions：VAPOR DIFFUSION, HANGING DROP；pH 6.5；296 K；magnesium sulfate heptahydrate, MES, pH 6.5, VAPOR DIFFUSION, HANGING DROP, temperature 296K	Resolution 3.10 Å R-free 0.284

Other States of the Same Protein in the Database

Other PDB	Difference from Current Entry 1OW0	Assembly / Oligomeric State	Construct	Mutations and Modifications	Ligands, Ions and Non-polymers	Method and Experimental Conditions	Structure Quality
1OVZ Crystal structure of human FcaRI Deposited 2003-03-27	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 22–216（195 aa） Fragment：ectodomain	Not recorded	NAG 2-acetamido-2-deoxy-beta-D-glucopyranose × 1 TRS 2-AMINO-2-HYDROXYMETHYL-PROPANE-1,3-DIOL × 1	X-RAY DIFFRACTION X-ray crystallization conditions VAPOR DIFFUSION, HANGING DROP；pH 6；296 K；PEG 8000, MES, pH 6.0, VAPOR DIFFUSION, HANGING DROP, temperature 296K	Resolution 3.00 Å R-free 0.292
1OVZ Crystal structure of human FcaRI Deposited 2003-03-27	Different oligomeric state Different experimental conditions Different structure-quality metrics	Assembly 2 Protein monomer Monomer；Protein × 1 PDB declaration: monomeric	Chain B 22–216（195 aa） Fragment：ectodomain	Not recorded	NAG 2-acetamido-2-deoxy-beta-D-glucopyranose × 2	X-RAY DIFFRACTION X-ray crystallization conditions VAPOR DIFFUSION, HANGING DROP；pH 6；296 K；PEG 8000, MES, pH 6.0, VAPOR DIFFUSION, HANGING DROP, temperature 296K	Resolution 3.00 Å R-free 0.292
1UCT Crystal structure of the extracellular fragment of Fc alpha Receptor I (CD89) Deposited 2003-04-21	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 20–229（210 aa） Fragment：RESIDUES 0-217	Not recorded	No recorded non-water small molecule	X-RAY DIFFRACTION X-ray crystallization conditions VAPOR DIFFUSION, HANGING DROP；pH 6；291 K；PEG4000, sodium citrate, ethanol glycol, pH 6.0, VAPOR DIFFUSION, HANGING DROP, temperature 291K	Resolution 2.10 Å R-free 0.239
8SKU Structure of human SIgA1 in complex with human CD89 (FcaR1) Deposited 2023-04-20	Different construct Different oligomeric state Different ligand/ion Different experimental method Different experimental conditions Different structure-quality metrics	Assembly 1 Other combination Heteromer；Protein × 8 PDB declaration: octameric	Chain R 22–216（195 aa） Chain S 22–216（195 aa）	Not recorded	NAG 2-acetamido-2-deoxy-beta-D-glucopyranose × 4	ELECTRON MICROSCOPY cryo-EM buffer pH 7 cryo-EM vitrification conditions Cryogen ETHANE	Resolution 3.20 Å
9OFR CRYSTAL STRUCTURE OF THE HUMAN IGA1 FC FRAGMENT-FC-ALPHA RECEPTOR (CD89) COMPLEX Deposited 2025-04-30	Different construct Different oligomeric state Different ligand/ion Different experimental conditions Different structure-quality metrics	Assembly 1 Other combination Heteromer；Protein × 4 PDB declaration: tetrameric	Chain C 22–216（195 aa） Chain D 22–216（195 aa）	Not recorded	NAG 2-acetamido-2-deoxy-beta-D-glucopyranose × 7	X-RAY DIFFRACTION X-ray crystallization conditions VAPOR DIFFUSION, HANGING DROP；pH 8；294 K；0.15M sodium chloride 0.1M Tris-HCl pH 8.0 8% PEG 6000	Resolution 2.65 Å R-free 0.264
9OFR CRYSTAL STRUCTURE OF THE HUMAN IGA1 FC FRAGMENT-FC-ALPHA RECEPTOR (CD89) COMPLEX Deposited 2025-04-30	Different construct Different oligomeric state Different ligand/ion Different experimental conditions Different structure-quality metrics	Assembly 2 Protein heterocomplex Heteromer；Protein × 4 PDB declaration: tetrameric	Chain F 22–216（195 aa） Chain H 22–216（195 aa）	Not recorded	NAG 2-acetamido-2-deoxy-beta-D-glucopyranose × 7	X-RAY DIFFRACTION X-ray crystallization conditions VAPOR DIFFUSION, HANGING DROP；pH 8；294 K；0.15M sodium chloride 0.1M Tris-HCl pH 8.0 8% PEG 6000	Resolution 2.65 Å R-free 0.264
9OFS Crystal structure of the human IGA2m2 FC fragment-FC-alpha receptor (CD89) complex Deposited 2025-04-30	Different construct Different oligomeric state Different ligand/ion Different experimental conditions Different structure-quality metrics	Assembly 1 Other combination Heteromer；Protein × 4 PDB declaration: tetrameric	Chain C 22–216（195 aa）	Not recorded	NAG 2-acetamido-2-deoxy-beta-D-glucopyranose × 8 CL CHLORIDE ION × 2	X-RAY DIFFRACTION X-ray crystallization conditions VAPOR DIFFUSION, HANGING DROP；pH 8；294 K；0.15M sodium chloride 0.1M Tris-HCl pH 8.0 20% PEG 1000	Resolution 1.95 Å R-free 0.253

5 other PDB entries and 7 assemblies. Open the comparison page and filter oligomeric states

View Construct and Data Evidence

UniProt name	FCAR_HUMAN
Isoform	—
PDB entities	2
Chains and sequence ranges	Author chain C； PDBConstruct 1–195； UniProt 22–216 Author chain D； PDBConstruct 1–195； UniProt 22–216

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	1ow0
Deposition date deposition_date	2003-03-27
Structure title title	Crystal structure of human FcaRI bound to IgA1-Fc
Keywords keywords	IgA1, FcaRI, CD89, antibody, Fc receptor, immunoglobulin-like domain, IMMUNE SYSTEM; IMMUNE SYSTEM
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	42.06 Å
Radius of gyration Rg (electron density) rg_electron	42.96 Å
Forward intensity I(0) i0	123159000.00
Molecular weight molecular_weight	89155.0 kDa
Excluded volume excluded_volume	111430 Å³
Envelope volume envelope_volume	164560 Å³
Hydration-shell volume shell_volume	37910 Å³
Envelope diameter envelope_diameter	189.6 Å
Shell Rg shell_rg	39.23 Å
Envelope Rg envelope_rg	43.99 Å
Shape Rg shape_rg	42.91 Å
Total Rg total_rg	42.86 Å
Total atoms total_atoms	6280
Residues n_residues	798
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	111.4 Å
Rg (real space) rg_real	38.43 Å
Rg uncertainty (real space) rg_real_error	0.41 Å
I(0) (real space) i0_real	1.1700e+08
I(0) uncertainty (real space) i0_real_error	1.7030e+06
Rg (reciprocal space) rg_reciprocal	42.07 Å
I(0) (reciprocal space) i0_reciprocal	123100000.0000
Solution quality estimate total_estimate	0.6838
Solution quality rating solution_quality	REASONABLE a REASONABLE solution
P(r) peaks n_peaks	1
Primary peak position r_peak_primary	41.0 Å
Skewness Skewness skewness	0.351
Kurtosis Kurtosis kurtosis	-0.598
Angular range angular_range	— – 0.1900 Å⁻¹
Current regularization parameter α current_alpha	0.8326
Highest regularization parameter α highest_alpha	5363000.0000
Real-space data points n_real_points	39
GNOM version gnom_version	4.1.3
Quality Criteria quality_criteria	AN1: 0.001; Oscil: 0.997; Stabil: 0.986; Sysdev: 0.000; Positv: 1.000; Valcen: 0.939; Smooth: 0.000

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5. Crystallography and Experiment 5. Crystallography & Experiment

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6. Entities and Polymers Entities & Polymers (8)

Entity 1 Entity 1 polymer

Description description	Ig alpha-1 chain C region
Molecular weight formula_weight	23226.4 kDa
Source method src_method	man
Copy count entity_count	2

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	A,B
Atom count atom_count	6280

ACHPRLSLHRPALEDLLLGSEANLTCTLTGLRDASGVTFTWTPSSGKSAVQGPPERDLCGCYSVSSVLPGCAEPWNHGKTFTCTAAYPESKTPLTATLSKSGNTFRPEVHLLPPPSEELALNELVTLTCLARGFSPKDVLVRWLQGSQELPREKYLTWASRQEPSQGTTTFAVTSILRVAAEDWKKGDTFSCMVGHEALPLAFTQKTIDRLAGK

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	Immunoglobulin alpha Fc receptor
Molecular weight formula_weight	23615.7 kDa
Source method src_method	man
Copy count entity_count	2

Polymer Polymer

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

QEGDFPMPFISAKSSPVIPLDGSVKIQCQAIREAYLTQLMIIKNSTYREIGRRLKFWNETDPEFVIDHMDANKAGRYQCQYRIGHYRFRYSDTLELVVTGLYGKPFLSADRGLVLMPGENISLTCSSAHIPFDRFSLAKEGELSLPQHQSGEHPANFSLGPVDLNVSGIYRCYGWYNRSPYLWSFPSNALELVVTAIDGRAHHHHHH

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	Trichoplusia ni

Entity 3 Entity 3 branched

Description description	;N-acetyl-alpha-neuraminic acid-(2-3)-beta-D-galactopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-2)-beta-D-mannopyranose-(1-6)-beta-D-mannopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-[beta-L-fucopyranose-(1-6)]2-acetamido-2-deoxy-beta-D-glucopyranose ;
Molecular weight formula_weight	1551.4 kDa
Source method src_method	man
Copy count entity_count	1

Entity 4 Entity 4 branched

Description description	;N-acetyl-alpha-neuraminic acid-(2-3)-beta-D-galactopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-2)-beta-D-mannopyranose-(1-6)-beta-D-mannopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-[alpha-L-fucopyranose-(1-6)]2-acetamido-2-deoxy-beta-D-glucopyranose ;
Molecular weight formula_weight	1551.4 kDa
Source method src_method	man
Copy count entity_count	1

Entity 5 Entity 5 branched

Description description	;alpha-D-mannopyranose-(1-3)-[beta-D-mannopyranose-(1-6)]alpha-D-mannopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose ;
Molecular weight formula_weight	910.8 kDa
Source method src_method	man
Copy count entity_count	2

Entity 6 Entity 6 branched

Description description	beta-D-mannopyranose-(1-4)-2-acetamido-2-deoxy-alpha-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	2

Entity 7 Entity 7 branched

Description description	;beta-D-mannopyranose-(1-4)-beta-D-mannopyranose-(1-2)-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	1073.0 kDa
Source method src_method	man
Copy count entity_count	2

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	2

▼

7. Fold Classification (SCOP + CATH) 16 domains

SCOP 2.08 (8 domains)

Domain ID domain_id	d1ow0a1
Class class	b — All beta proteins
Fold Fold fold	b.1 — Immunoglobulin-like beta-sandwich
Superfamily Superfamily superfamily	b.1.1 — Immunoglobulin
Family Family family	b.1.1.2 — C1 set domains (antibody constant domain-like)

Domain ID domain_id	d1ow0a2
Class class	b — All beta proteins
Fold Fold fold	b.1 — Immunoglobulin-like beta-sandwich
Superfamily Superfamily superfamily	b.1.1 — Immunoglobulin
Family Family family	b.1.1.2 — C1 set domains (antibody constant domain-like)

Domain ID domain_id	d1ow0b1
Class class	b — All beta proteins
Fold Fold fold	b.1 — Immunoglobulin-like beta-sandwich
Superfamily Superfamily superfamily	b.1.1 — Immunoglobulin
Family Family family	b.1.1.2 — C1 set domains (antibody constant domain-like)

Domain ID domain_id	d1ow0b2
Class class	b — All beta proteins
Fold Fold fold	b.1 — Immunoglobulin-like beta-sandwich
Superfamily Superfamily superfamily	b.1.1 — Immunoglobulin
Family Family family	b.1.1.2 — C1 set domains (antibody constant domain-like)

Domain ID domain_id	d1ow0c1
Class class	b — All beta proteins
Fold Fold fold	b.1 — Immunoglobulin-like beta-sandwich
Superfamily Superfamily superfamily	b.1.1 — Immunoglobulin
Family Family family	b.1.1.4 — I set domains

Domain ID domain_id	d1ow0c2
Class class	b — All beta proteins
Fold Fold fold	b.1 — Immunoglobulin-like beta-sandwich
Superfamily Superfamily superfamily	b.1.1 — Immunoglobulin
Family Family family	b.1.1.4 — I set domains

Domain ID domain_id	d1ow0d1
Class class	b — All beta proteins
Fold Fold fold	b.1 — Immunoglobulin-like beta-sandwich
Superfamily Superfamily superfamily	b.1.1 — Immunoglobulin
Family Family family	b.1.1.4 — I set domains

Domain ID domain_id	d1ow0d2
Class class	b — All beta proteins
Fold Fold fold	b.1 — Immunoglobulin-like beta-sandwich
Superfamily Superfamily superfamily	b.1.1 — Immunoglobulin
Family Family family	b.1.1.4 — I set domains

CATH v4.4 (8 domains)

Domain ID domain_id	1ow0A01
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	10 — Immunoglobulins

Domain ID domain_id	1ow0A02
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	10 — Immunoglobulins

Domain ID domain_id	1ow0B01
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	10 — Immunoglobulins

Domain ID domain_id	1ow0B02
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	10 — Immunoglobulins

Domain ID domain_id	1ow0C01
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	10 — Immunoglobulins

Domain ID domain_id	1ow0C02
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	10 — Immunoglobulins

Domain ID domain_id	1ow0D01
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	10 — Immunoglobulins

Domain ID domain_id	1ow0D02
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	10 — Immunoglobulins

▶

8. Citations (2)

▶

Unit-cell length a length_a	142.987 Å
Unit-cell length b length_b	142.987 Å
Unit-cell length c length_c	67.655 Å
Unit-cell angle α angle_alpha	90.00 °
Unit-cell angle β angle_beta	90.00 °
Unit-cell angle γ angle_gamma	120.00 °
Molecules per unit cell Z z_pdb	6

Space group space_group	P 3
Space-group number int_tables_number	143
Crystal system crystal_system	—

Resolution resolution	3.100 Å
Low-resolution limit resolution_low	29.690 Å
R factor r_factor	0.2520
R_work r_work	0.2520
R_free r_free	0.2840

fit	/app/data/saxs_computation/ow/1ow0/1ow0.fit
pddf	/app/data/pr_computation/ow/1ow0/1ow0.pr.out
profile	/app/data/saxs_computation/ow/1ow0/1ow0.dat

Crystal structure of human FcaRI bound to IgA1-Fc

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

Ig alpha-1 chain C region

State in the Current Structure

Other States of the Same Protein in the Database

Immunoglobulin alpha Fc receptor

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 (8)

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 branched

Entity 7 Entity 7 branched

Entity 8 Entity 8 non-polymer

7. Fold Classification (SCOP + CATH) 16 domains

SCOP 2.08 (8 domains)

CATH v4.4 (8 domains)

8. Citations (2)

9. Files and Curves (10)

Files (7)

Curves (3)