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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：P20273 New Search
6PDB entries
16Biological assembly
16chain/assembly records
Main Difference Dimensions in This Set
Different construct Different mutation/modification Different assembly state Different ligand/ion 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
5VKJ Crystal structure of human CD22 Ig domains 1-3 Deposited 2017-04-21 Assembly 1 Other combination Monomer；Protein × 1 PDB declaration: monomeric（1） Consistent with protein count
Chain A 20–330（311 aa） Fragment：Extracellular domain residues 20-330
Mutation：N67A,N112A,N135A,N164A,N231A GOL GLYCEROL × 4 X-RAY DIFFRACTION
X-ray crystallization conditions VAPOR DIFFUSION；293 K；30% PEG 4000, 0.2 M lithium chloride and 0.1 M Tris pH 8.5
Resolution 2.12 Å R-free 0.232
5VKM Crystal structure of human CD22 Ig domains 1-3 in complex with alpha 2-6 sialyllactose Deposited 2017-04-21 Assembly 1 Other combination Monomer；Protein × 1 PDB declaration: monomeric（1） Consistent with protein count
Chain A 20–330（311 aa） Fragment：Extracellular domain residues 20-330
Mutation：N67A,N112A,N135A,N164A,N231A GOL GLYCEROL × 1 X-RAY DIFFRACTION
X-ray crystallization conditions VAPOR DIFFUSION；293 K；30% PEG 4000, 0.2 M lithium chloride and 0.1 M Tris pH 8.5
Resolution 2.20 Å R-free 0.254
5VL3 CD22 d1-d3 in complex with therapeutic Fab Epratuzumab Deposited 2017-04-24 Assembly 1 Other combination Heteromer；Protein × 3 PDB declaration: trimeric（3） Consistent with protein count
Chain Q 22–330（309 aa）
Not recorded No recorded non-water small molecule X-RAY DIFFRACTION
X-ray crystallization conditions VAPOR DIFFUSION；293 K；20 mM Tris pH 8.0 and 150 mM NaCl, 5mg/mL
Resolution 3.10 Å R-free 0.295
5VL3 CD22 d1-d3 in complex with therapeutic Fab Epratuzumab Deposited 2017-04-24 Assembly 2 Other combination Heteromer；Protein × 3 PDB declaration: trimeric（3） Consistent with protein count
Chain R 22–330（309 aa）
Not recorded No recorded non-water small molecule X-RAY DIFFRACTION
X-ray crystallization conditions VAPOR DIFFUSION；293 K；20 mM Tris pH 8.0 and 150 mM NaCl, 5mg/mL
Resolution 3.10 Å R-free 0.295
5VL3 CD22 d1-d3 in complex with therapeutic Fab Epratuzumab Deposited 2017-04-24 Assembly 3 Other combination Heteromer；Protein × 3 PDB declaration: trimeric（3） Consistent with protein count
Chain S 22–330（309 aa）
Not recorded GOL GLYCEROL × 1 X-RAY DIFFRACTION
X-ray crystallization conditions VAPOR DIFFUSION；293 K；20 mM Tris pH 8.0 and 150 mM NaCl, 5mg/mL
Resolution 3.10 Å R-free 0.295
5VL3 CD22 d1-d3 in complex with therapeutic Fab Epratuzumab Deposited 2017-04-24 Assembly 4 Other combination Heteromer；Protein × 3 PDB declaration: trimeric（3） Consistent with protein count
Chain T 22–330（309 aa）
Not recorded No recorded non-water small molecule X-RAY DIFFRACTION
X-ray crystallization conditions VAPOR DIFFUSION；293 K；20 mM Tris pH 8.0 and 150 mM NaCl, 5mg/mL
Resolution 3.10 Å R-free 0.295
9RM3 Crystal structure of human CD22 Ig domains 1-3 in complex with modified sialoside 17 Deposited 2025-06-17 Assembly 1 Other combination Monomer；Protein × 1 PDB declaration: monomeric（1） Consistent with protein count
Chain A 20–330（311 aa）
Not recorded SO4 SULFATE ION × 1 A1JJP (2R,4S,5R,6R)-5-acetamido-2-[[(2R,3R,4S,5R,6S)-6-[(2R,3S,4R,5R,6R)-5-acetamido-6-(2-azanylethoxy)-2-(hydroxymethyl)-4-oxidanyl-oxan-3-yl]oxy-3,4,5-tris(oxidanyl)oxan-2-yl]methoxy]-6-[(1R,2R)-1,2-bis(oxidanyl)-3-[(3-phenoxyphenyl)carbonylamino]propyl]-4-oxidanyl-oxane-2-carboxylic acid × 1 X-RAY DIFFRACTION
X-ray crystallization conditions VAPOR DIFFUSION, HANGING DROP；277 K；20% PEG 3350, 0.2 M ammonium sulphate
Resolution 2.86 Å R-free 0.289
9RM3 Crystal structure of human CD22 Ig domains 1-3 in complex with modified sialoside 17 Deposited 2025-06-17 Assembly 2 Other combination Monomer；Protein × 1 PDB declaration: monomeric（1） Consistent with protein count
Chain B 20–330（311 aa）
Not recorded SO4 SULFATE ION × 1 A1JJP (2R,4S,5R,6R)-5-acetamido-2-[[(2R,3R,4S,5R,6S)-6-[(2R,3S,4R,5R,6R)-5-acetamido-6-(2-azanylethoxy)-2-(hydroxymethyl)-4-oxidanyl-oxan-3-yl]oxy-3,4,5-tris(oxidanyl)oxan-2-yl]methoxy]-6-[(1R,2R)-1,2-bis(oxidanyl)-3-[(3-phenoxyphenyl)carbonylamino]propyl]-4-oxidanyl-oxane-2-carboxylic acid × 1 X-RAY DIFFRACTION
X-ray crystallization conditions VAPOR DIFFUSION, HANGING DROP；277 K；20% PEG 3350, 0.2 M ammonium sulphate
Resolution 2.86 Å R-free 0.289
9RM3 Crystal structure of human CD22 Ig domains 1-3 in complex with modified sialoside 17 Deposited 2025-06-17 Assembly 3 Other combination Monomer；Protein × 1 PDB declaration: monomeric（1） Consistent with protein count
Chain C 20–330（311 aa）
Not recorded SO4 SULFATE ION × 1 A1JJP (2R,4S,5R,6R)-5-acetamido-2-[[(2R,3R,4S,5R,6S)-6-[(2R,3S,4R,5R,6R)-5-acetamido-6-(2-azanylethoxy)-2-(hydroxymethyl)-4-oxidanyl-oxan-3-yl]oxy-3,4,5-tris(oxidanyl)oxan-2-yl]methoxy]-6-[(1R,2R)-1,2-bis(oxidanyl)-3-[(3-phenoxyphenyl)carbonylamino]propyl]-4-oxidanyl-oxane-2-carboxylic acid × 1 X-RAY DIFFRACTION
X-ray crystallization conditions VAPOR DIFFUSION, HANGING DROP；277 K；20% PEG 3350, 0.2 M ammonium sulphate
Resolution 2.86 Å R-free 0.289
9RM3 Crystal structure of human CD22 Ig domains 1-3 in complex with modified sialoside 17 Deposited 2025-06-17 Assembly 4 Other combination Monomer；Protein × 1 PDB declaration: monomeric（1） Consistent with protein count
Chain D 20–330（311 aa）
Not recorded A1JJP (2R,4S,5R,6R)-5-acetamido-2-[[(2R,3R,4S,5R,6S)-6-[(2R,3S,4R,5R,6R)-5-acetamido-6-(2-azanylethoxy)-2-(hydroxymethyl)-4-oxidanyl-oxan-3-yl]oxy-3,4,5-tris(oxidanyl)oxan-2-yl]methoxy]-6-[(1R,2R)-1,2-bis(oxidanyl)-3-[(3-phenoxyphenyl)carbonylamino]propyl]-4-oxidanyl-oxane-2-carboxylic acid × 1 X-RAY DIFFRACTION
X-ray crystallization conditions VAPOR DIFFUSION, HANGING DROP；277 K；20% PEG 3350, 0.2 M ammonium sulphate
Resolution 2.86 Å R-free 0.289
9RO7 Crystal structure of human CD22 Ig domains 1-3 in complex with modified sialoside 7-012 Deposited 2025-06-20 Assembly 1 Other combination Monomer；Protein × 1 PDB declaration: monomeric（1） Consistent with protein count
Chain A 20–330（311 aa）
Not recorded A1JJO (2R,4S,5R,6R)-5-acetamido-6-[(1S,2S)-1,2-bis(oxidanyl)-3-[(4-phenylphenyl)carbonylamino]propyl]-2-[[1-[(2R)-3-(2-methyl-5-nitro-imidazol-1-yl)-2-oxidanyl-propyl]-1,2,3-triazol-4-yl]methyl]-4-oxidanyl-oxane-2-carboxylic acid × 1 SO4 SULFATE ION × 1 X-RAY DIFFRACTION
X-ray crystallization conditions VAPOR DIFFUSION, SITTING DROP；277 K；20% PEG 3350, 0.2 M ammonium sulphate
Resolution 3.15 Å R-free 0.298
9RO7 Crystal structure of human CD22 Ig domains 1-3 in complex with modified sialoside 7-012 Deposited 2025-06-20 Assembly 2 Other combination Monomer；Protein × 1 PDB declaration: monomeric（1） Consistent with protein count
Chain B 20–330（311 aa）
Not recorded A1JJO (2R,4S,5R,6R)-5-acetamido-6-[(1S,2S)-1,2-bis(oxidanyl)-3-[(4-phenylphenyl)carbonylamino]propyl]-2-[[1-[(2R)-3-(2-methyl-5-nitro-imidazol-1-yl)-2-oxidanyl-propyl]-1,2,3-triazol-4-yl]methyl]-4-oxidanyl-oxane-2-carboxylic acid × 1 SO4 SULFATE ION × 1 X-RAY DIFFRACTION
X-ray crystallization conditions VAPOR DIFFUSION, SITTING DROP；277 K；20% PEG 3350, 0.2 M ammonium sulphate
Resolution 3.15 Å R-free 0.298
9RO7 Crystal structure of human CD22 Ig domains 1-3 in complex with modified sialoside 7-012 Deposited 2025-06-20 Assembly 3 Other combination Monomer；Protein × 1 PDB declaration: monomeric（1） Consistent with protein count
Chain C 20–330（311 aa）
Not recorded A1JJO (2R,4S,5R,6R)-5-acetamido-6-[(1S,2S)-1,2-bis(oxidanyl)-3-[(4-phenylphenyl)carbonylamino]propyl]-2-[[1-[(2R)-3-(2-methyl-5-nitro-imidazol-1-yl)-2-oxidanyl-propyl]-1,2,3-triazol-4-yl]methyl]-4-oxidanyl-oxane-2-carboxylic acid × 1 SO4 SULFATE ION × 2 X-RAY DIFFRACTION
X-ray crystallization conditions VAPOR DIFFUSION, SITTING DROP；277 K；20% PEG 3350, 0.2 M ammonium sulphate
Resolution 3.15 Å R-free 0.298
9RO7 Crystal structure of human CD22 Ig domains 1-3 in complex with modified sialoside 7-012 Deposited 2025-06-20 Assembly 4 Other combination Monomer；Protein × 1 PDB declaration: monomeric（1） Consistent with protein count
Chain D 20–330（311 aa）
Not recorded A1JJO (2R,4S,5R,6R)-5-acetamido-6-[(1S,2S)-1,2-bis(oxidanyl)-3-[(4-phenylphenyl)carbonylamino]propyl]-2-[[1-[(2R)-3-(2-methyl-5-nitro-imidazol-1-yl)-2-oxidanyl-propyl]-1,2,3-triazol-4-yl]methyl]-4-oxidanyl-oxane-2-carboxylic acid × 1 SO4 SULFATE ION × 1 X-RAY DIFFRACTION
X-ray crystallization conditions VAPOR DIFFUSION, SITTING DROP；277 K；20% PEG 3350, 0.2 M ammonium sulphate
Resolution 3.15 Å R-free 0.298
9ROB Crystal structure of human CD22 Ig domains 1-3 in complex with modified sialoside 1B Deposited 2025-06-20 Assembly 1 Other combination Monomer；Protein × 1 PDB declaration: monomeric（1） Consistent with protein count
Chain A 20–330（311 aa）
Not recorded A1JJN (2R,4S,5R,6R)-5-acetamido-2-[[2,3-bis(chloranyl)phenyl]methoxy]-6-[(1R,2R)-1,2-bis(oxidanyl)-3-[(4-phenylphenyl)carbonylamino]propyl]-4-oxidanyl-oxane-2-carboxylic acid × 1 GOL GLYCEROL × 1 X-RAY DIFFRACTION
X-ray crystallization conditions VAPOR DIFFUSION, SITTING DROP；293 K；24% PEG 4000, 0.6 M NaCl, 0.1 M MES pH 6.5
Resolution 2.70 Å R-free 0.267
9ROB Crystal structure of human CD22 Ig domains 1-3 in complex with modified sialoside 1B Deposited 2025-06-20 Assembly 2 Other combination Monomer；Protein × 1 PDB declaration: monomeric（1） Consistent with protein count
Chain B 20–330（311 aa）
Not recorded A1JJN (2R,4S,5R,6R)-5-acetamido-2-[[2,3-bis(chloranyl)phenyl]methoxy]-6-[(1R,2R)-1,2-bis(oxidanyl)-3-[(4-phenylphenyl)carbonylamino]propyl]-4-oxidanyl-oxane-2-carboxylic acid × 1 GOL GLYCEROL × 2 X-RAY DIFFRACTION
X-ray crystallization conditions VAPOR DIFFUSION, SITTING DROP；293 K；24% PEG 4000, 0.6 M NaCl, 0.1 M MES pH 6.5
Resolution 2.70 Å R-free 0.267

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.