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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：P00921 New Search
14PDB entries
22Biological assembly
22chain/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
1G6V Complex of the camelid heavy-chain antibody fragment CAB-CA05 with bovine carbonic anhydrase Deposited 2000-11-08 Assembly 1 Protein heterocomplex Heteromer；Protein × 2 PDB declaration: dimeric（2） Consistent with protein count
Chain A 0–260（261 aa）
Not recorded ZN ZINC ION × 1 X-RAY DIFFRACTION
X-ray crystallization conditions VAPOR DIFFUSION, HANGING DROP；pH 5.6；293 K；PEG 8000, sodium citrate, pH 5.6, VAPOR DIFFUSION, HANGING DROP, temperature 293K
Resolution 3.50 Å R-free 0.276
1V9E Crystal Structure Analysis of Bovine Carbonic Anhydrase II Deposited 2004-01-26 Assembly 1 Protein monomer Monomer；Protein × 1 PDB declaration: monomeric（1） Consistent with protein count
Chain A 1–259（259 aa）
Not recorded ZN ZINC ION × 1 X-RAY DIFFRACTION
X-ray crystallization conditions SMALL TUBES；pH 7.5；277 K；50mM Tris-HCl, 2.4M Ammonium sulfate, pH 7.5, SMALL TUBES, temperature 277K
Resolution 1.95 Å R-free 0.298
1V9E Crystal Structure Analysis of Bovine Carbonic Anhydrase II Deposited 2004-01-26 Assembly 2 Protein monomer Monomer；Protein × 1 PDB declaration: monomeric（1） Consistent with protein count
Chain B 1–259（259 aa）
Not recorded ZN ZINC ION × 1 X-RAY DIFFRACTION
X-ray crystallization conditions SMALL TUBES；pH 7.5；277 K；50mM Tris-HCl, 2.4M Ammonium sulfate, pH 7.5, SMALL TUBES, temperature 277K
Resolution 1.95 Å R-free 0.298
1V9I Crystal Structure Analysis of the site specific mutant (Q253C) of bovine carbonic anhydrase II Deposited 2004-01-26 Assembly 1 Protein monomer Monomer；Protein × 1 PDB declaration: monomeric（1） Consistent with protein count
Chain C 1–259（259 aa）
Mutation：Q253C ZN ZINC ION × 1 X-RAY DIFFRACTION
X-ray crystallization conditions SMALL TUBES；pH 7.5；277 K；50mM Tris-HCl, 3mM NaN3, 2.3M Ammonium Sulfate, pH 7.5, SMALL TUBES, temperature 277K
Resolution 2.95 Å R-free 0.346
23OM Crystal Structure Analysis of Bovine Carbonic Anhydrase II to 5-(2-morpholin-4-ylcarbonyl-1,3-oxazol-5-yl)thiophene-2-sulfonamide. Deposited 2026-02-12 Assembly 1 Protein monomer Monomer；Protein × 1 PDB declaration: monomeric（1） Consistent with protein count
Chain A 2–260（259 aa）
Not recorded 8V5 5-(2-morpholin-4-ylcarbonyl-1,3-oxazol-5-yl)thiophene-2-sulfonamide × 1 BOG octyl beta-D-glucopyranoside × 1 GOL GLYCEROL × 3 ZN ZINC ION × 1 ACT ACETATE ION × 3 X-RAY DIFFRACTION
X-ray crystallization conditions VAPOR DIFFUSION, HANGING DROP；pH 8.5；291 K；2M ammonium sulfate, 0.1M Tris base Buffer
Resolution 1.70 Å R-free 0.250
23OM Crystal Structure Analysis of Bovine Carbonic Anhydrase II to 5-(2-morpholin-4-ylcarbonyl-1,3-oxazol-5-yl)thiophene-2-sulfonamide. Deposited 2026-02-12 Assembly 2 Protein monomer Monomer；Protein × 1 PDB declaration: monomeric（1） Consistent with protein count
Chain B 2–260（259 aa）
Not recorded 8V5 5-(2-morpholin-4-ylcarbonyl-1,3-oxazol-5-yl)thiophene-2-sulfonamide × 1 BOG octyl beta-D-glucopyranoside × 1 GOL GLYCEROL × 3 ZN ZINC ION × 1 ACT ACETATE ION × 1 SO4 SULFATE ION × 1 X-RAY DIFFRACTION
X-ray crystallization conditions VAPOR DIFFUSION, HANGING DROP；pH 8.5；291 K；2M ammonium sulfate, 0.1M Tris base Buffer
Resolution 1.70 Å R-free 0.250
23ON Crystal Structure Analysis of Bovine Carbonic Anhydrase II to 4-2-methyl-1,3-oxazol-5-ylbenzenesulfonamide Deposited 2026-02-12 Assembly 1 Protein monomer Monomer；Protein × 1 PDB declaration: monomeric（1） Consistent with protein count
Chain A 2–260（259 aa）
Not recorded 8V8 4-(2-methyl-1,3-oxazol-5-yl)benzenesulfonamide × 1 GOL GLYCEROL × 3 ACT ACETATE ION × 1 ZN ZINC ION × 1 X-RAY DIFFRACTION
X-ray crystallization conditions VAPOR DIFFUSION, HANGING DROP；pH 8.5；291 K；2M ammonium sulfate, 0.1M Tris-base Buffer
Resolution 1.50 Å R-free 0.200
23ON Crystal Structure Analysis of Bovine Carbonic Anhydrase II to 4-2-methyl-1,3-oxazol-5-ylbenzenesulfonamide Deposited 2026-02-12 Assembly 2 Protein monomer Monomer；Protein × 1 PDB declaration: monomeric（1） Consistent with protein count
Chain B 2–260（259 aa）
Not recorded 8V8 4-(2-methyl-1,3-oxazol-5-yl)benzenesulfonamide × 1 GOL GLYCEROL × 3 ACT ACETATE ION × 2 ZN ZINC ION × 1 X-RAY DIFFRACTION
X-ray crystallization conditions VAPOR DIFFUSION, HANGING DROP；pH 8.5；291 K；2M ammonium sulfate, 0.1M Tris-base Buffer
Resolution 1.50 Å R-free 0.200
4CNR Surface residue engineering of bovine carbonic anhydrase to an extreme halophilic enzyme for potential application in postcombustion CO2 capture Deposited 2014-01-24 Assembly 1 Protein monomer Monomer；Protein × 1 PDB declaration: monomeric（1） Consistent with protein count
Chain A 1–260（260 aa）
Mutation：YES ZN ZINC ION × 1 X-RAY DIFFRACTION
X-ray crystallization conditions VAPOR DIFFUSION；pH 5.5；281 K；10 MG/ML PROTEIN WITH 30% PEG 1500 AT 8C, pH 5.5
Resolution 2.29 Å R-free 0.236
4CNR Surface residue engineering of bovine carbonic anhydrase to an extreme halophilic enzyme for potential application in postcombustion CO2 capture Deposited 2014-01-24 Assembly 2 Protein monomer Monomer；Protein × 1 PDB declaration: monomeric（1） Consistent with protein count
Chain B 1–260（260 aa）
Mutation：YES ZN ZINC ION × 1 X-RAY DIFFRACTION
X-ray crystallization conditions VAPOR DIFFUSION；pH 5.5；281 K；10 MG/ML PROTEIN WITH 30% PEG 1500 AT 8C, pH 5.5
Resolution 2.29 Å R-free 0.236
4CNR Surface residue engineering of bovine carbonic anhydrase to an extreme halophilic enzyme for potential application in postcombustion CO2 capture Deposited 2014-01-24 Assembly 3 Protein monomer Monomer；Protein × 1 PDB declaration: monomeric（1） Consistent with protein count
Chain C 1–260（260 aa）
Mutation：YES ZN ZINC ION × 1 X-RAY DIFFRACTION
X-ray crystallization conditions VAPOR DIFFUSION；pH 5.5；281 K；10 MG/ML PROTEIN WITH 30% PEG 1500 AT 8C, pH 5.5
Resolution 2.29 Å R-free 0.236
4CNR Surface residue engineering of bovine carbonic anhydrase to an extreme halophilic enzyme for potential application in postcombustion CO2 capture Deposited 2014-01-24 Assembly 4 Protein monomer Monomer；Protein × 1 PDB declaration: monomeric（1） Consistent with protein count
Chain D 1–260（260 aa）
Mutation：YES ZN ZINC ION × 1 X-RAY DIFFRACTION
X-ray crystallization conditions VAPOR DIFFUSION；pH 5.5；281 K；10 MG/ML PROTEIN WITH 30% PEG 1500 AT 8C, pH 5.5
Resolution 2.29 Å R-free 0.236
4CNV Surface residue engineering of bovine carbonic anhydrase to an extreme halophilic enzyme for potential application in postcombustion CO2 capture Deposited 2014-01-25 Assembly 1 Protein monomer Monomer；Protein × 1 PDB declaration: monomeric（1） Consistent with protein count
Chain A 1–260（260 aa）
Mutation：YES ZN ZINC ION × 1 GOL GLYCEROL × 2 X-RAY DIFFRACTION
X-ray crystallization conditions pH 6；PROTEIN WAS AT 10 MG/ML; THE RESERVOIR SOLUTION WAS 5% PEG 1000, 30% PEG 600, 10% GLYCEROL, 100 MM SODIUM MES BUFFER AT PH 6. SEEDS OF THE MUT1 FORM WERE USED TO OBTAIN THESE CRYSTALS.
Resolution 1.62 Å R-free 0.182
4CNW Surface residue engineering of bovine carbonic anhydrase to an extreme halophilic enzyme for potential application in postcombustion CO2 capture Deposited 2014-01-25 Assembly 1 Protein monomer Monomer；Protein × 1 PDB declaration: monomeric（1） Consistent with protein count
Chain A 1–260（260 aa）
Mutation：YES ZN ZINC ION × 1 X-RAY DIFFRACTION
X-ray crystallization conditions pH 8；PROTEIN WAS AT 10 MG/ML. THE RESERVOIR CONDITIONS WERE: 25% PEG MME 2000, 200 MM CALCIUM ACETATE, 50 MM TRIS BUFFER PH 8.0. THE CRYSTALS WERE OBTAINED THROUGH CROSS SEEDING FROM A DIFFERENT MUTANT CA-II CRYSTAL.
Resolution 2.03 Å R-free 0.259
4CNW Surface residue engineering of bovine carbonic anhydrase to an extreme halophilic enzyme for potential application in postcombustion CO2 capture Deposited 2014-01-25 Assembly 2 Protein monomer Monomer；Protein × 1 PDB declaration: monomeric（1） Consistent with protein count
Chain B 1–260（260 aa）
Mutation：YES ZN ZINC ION × 1 CA CALCIUM ION × 1 X-RAY DIFFRACTION
X-ray crystallization conditions pH 8；PROTEIN WAS AT 10 MG/ML. THE RESERVOIR CONDITIONS WERE: 25% PEG MME 2000, 200 MM CALCIUM ACETATE, 50 MM TRIS BUFFER PH 8.0. THE CRYSTALS WERE OBTAINED THROUGH CROSS SEEDING FROM A DIFFERENT MUTANT CA-II CRYSTAL.
Resolution 2.03 Å R-free 0.259
4CNX Surface residue engineering of bovine carbonic anhydrase to an extreme halophilic enzyme for potential application in postcombustion CO2 capture Deposited 2014-01-25 Assembly 1 Protein monomer Monomer；Protein × 1 PDB declaration: monomeric（1） Consistent with protein count
Chain A 1–260（260 aa）
Mutation：YES ZN ZINC ION × 1 PEG DI(HYDROXYETHYL)ETHER × 1 X-RAY DIFFRACTION
X-ray crystallization conditions VAPOR DIFFUSION；pH 5.5；281 K；PROTEIN WAS AT 10 MG/ML. THE RESERVOIR CONDITIONS WERE: 40% PEG 600, 100 MM SODIUM CITRATE AT PH 5.5 SET UP AT 8C. CROSS SEEDING FROM OTHER MUTANT CA-II CRYSTALS WAS USED TO OBTAIN THESE CRYSTALS.
Resolution 1.23 Å R-free 0.147
5A25 Rational engineering of a mesophilic carbonic anhydrase to an extreme halotolerant biocatalyst Deposited 2015-05-12 Assembly 1 Protein monomer Monomer；Protein × 1 PDB declaration: monomeric（1） Consistent with protein count
Chain A 1–260（260 aa）
Not recorded ZN ZINC ION × 1 GOL GLYCEROL × 1 NA SODIUM ION × 2 BOG octyl beta-D-glucopyranoside × 1 X-RAY DIFFRACTION
X-ray crystallization conditions pH 8.2；150 NL 20 MG/ML PROTEIN PLUS 150 NL RESERVOIR CONSISTING OF 50 MM TRIS PH 8.2, 2.3 M AMMONIUM SULFATE, 0.023 (W/V) N-OCTYL-B-D-GLUCOPYRANOSIDE
Resolution 1.90 Å R-free 0.197
5A25 Rational engineering of a mesophilic carbonic anhydrase to an extreme halotolerant biocatalyst Deposited 2015-05-12 Assembly 2 Protein monomer Monomer；Protein × 1 PDB declaration: monomeric（1） Consistent with protein count
Chain B 1–260（260 aa）
Not recorded ZN ZINC ION × 1 NA SODIUM ION × 2 BOG octyl beta-D-glucopyranoside × 2 X-RAY DIFFRACTION
X-ray crystallization conditions pH 8.2；150 NL 20 MG/ML PROTEIN PLUS 150 NL RESERVOIR CONSISTING OF 50 MM TRIS PH 8.2, 2.3 M AMMONIUM SULFATE, 0.023 (W/V) N-OCTYL-B-D-GLUCOPYRANOSIDE
Resolution 1.90 Å R-free 0.197
5EZT Peracetylated Bovine Carbonic Anhydrase II Deposited 2015-11-26 Assembly 1 Protein monomer Monomer；Protein × 1 PDB declaration: monomeric（1） Consistent with protein count
Chain X 4–260（257 aa） Fragment：UNP residues 4-260
Non-standard monomer：Yes (specific site not provided by mmCIF) ZN ZINC ION × 1 X-RAY DIFFRACTION
X-ray crystallization conditions VAPOR DIFFUSION, HANGING DROP；pH 7；277.15 K；1.6M ammonium sulfate, tris
Resolution 1.54 Å R-free 0.239
6SKS Crystal structure of bovine carbonic anhydrase II in complex with a benzenesulfonamide-based ligand (SH1) Deposited 2019-08-16 Assembly 1 Protein monomer Monomer；Protein × 1 PDB declaration: monomeric（1） Consistent with protein count
Chain A 1–260（260 aa）
Not recorded CU COPPER (II) ION × 4 ZN ZINC ION × 1 GOL GLYCEROL × 2 E68 ~{N}-[2-[2-(1~{H}-imidazol-4-yl)ethylamino]-2-oxidanylidene-ethyl]-4-sulfamoyl-benzamide × 1 X-RAY DIFFRACTION
X-ray crystallization conditions VAPOR DIFFUSION, SITTING DROP；pH 7.5；291 K；100mM HEPES pH7.5, 14% PEG3350, 20% Glycerol, 5mM CuCl2
Resolution 1.75 Å R-free 0.194
6SKT Crystal structure of bovine carbonic anhydrase II in complex with a benzenesulfonamide-based ligand (SH0) Deposited 2019-08-16 Assembly 1 Protein monomer Monomer；Protein × 1 PDB declaration: monomeric（1） Consistent with protein count
Chain A 1–260（260 aa）
Not recorded CU COPPER (II) ION × 2 ZN ZINC ION × 1 GOL GLYCEROL × 1 E6B ~{N}-[2-(1~{H}-imidazol-4-yl)ethyl]-4-sulfamoyl-benzamide × 1 X-RAY DIFFRACTION
X-ray crystallization conditions VAPOR DIFFUSION, SITTING DROP；pH 7.5；291 K；100mM HEPES pH7.5, 14% PEG3350, 20% Glycerol, 5mM CuCl2
Resolution 1.90 Å R-free 0.204
6SKV Crystal structure of bovine carbonic anhydrase II in complex with a benzenesulfonamide-based ligand (SH2) Deposited 2019-08-16 Assembly 1 Protein monomer Monomer；Protein × 1 PDB declaration: monomeric（1） Consistent with protein count
Chain A 1–260（260 aa）
Not recorded ZN ZINC ION × 1 CU COPPER (II) ION × 3 GOL GLYCEROL × 2 E5Z ~{N}-[3-[(~{E})-2-(1~{H}-imidazol-5-yl)ethylideneamino]-3-oxidanylidene-propyl]-4-sulfamoyl-benzamide × 1 X-RAY DIFFRACTION
X-ray crystallization conditions VAPOR DIFFUSION, SITTING DROP；pH 7.5；291 K；100mM HEPES pH7.5, 14% PEG3350, 20% Glycerol, 5mM CuCl2.
Resolution 1.75 Å R-free 0.189

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.