6IM1
Crystal structure of a highly thermostable carbonic anhydrase from Persephonella marina EX-H1
Summary for 6IM1
| Entry DOI | 10.2210/pdb6im1/pdb |
| Descriptor | Carbonic anhydrase (Carbonate dehydratase), ZINC ION, CALCIUM ION, ... (5 entities in total) |
| Functional Keywords | carbonic anhydrase, zinc metalloenzyme, persephonella marina ex-h1, co2 mineralization, co2 capture and storage, lyase |
| Biological source | Persephonella marina (strain DSM 14350 / EX-H1) |
| Total number of polymer chains | 6 |
| Total formula weight | 168113.95 |
| Authors | Jin, M.S.,Kim, S.,Sung, J.,Yeon, J.,Choi, S.H. (deposition date: 2018-10-21, release date: 2019-07-17, Last modification date: 2024-10-23) |
| Primary citation | Kim, S.,Sung, J.,Yeon, J.,Choi, S.H.,Jin, M.S. Crystal Structure of a Highly Thermostable alpha-Carbonic Anhydrase from Persephonella marina EX-H1. Mol.Cells, 42:460-469, 2019 Cited by PubMed Abstract: Bacterial α-type carbonic anhydrase (α-CA) is a zinc metalloenzyme that catalyzes the reversible and extremely rapid interconversion of carbon dioxide to bicarbonate. In this study, we report the first crystal structure of a hyperthermostable α-CA from Persephonella marina EXH1 ( CA) in the absence and presence of competitive inhibitor, acetazolamide. The structure reveals a compactly folded pm CA homodimer in which each monomer consists of a 10-stranded β-sheet in the center. The catalytic zinc ion is coordinated by three highly conserved histidine residues with an exchangeable fourth ligand (a water molecule, a bicarbonate anion, or the sulfonamide group of acetazolamide). Together with an intramolecular disulfide bond, extensive interfacial networks of hydrogen bonds, ionic and hydrophobic interactions stabilize the dimeric structure and are likely responsible for the high thermal stability. We also identified novel binding sites for calcium ions at the crystallographic interface, which serve as molecular glue linking negatively charged and otherwise repulsive surfaces. Furthermore, this large negatively charged patch appears to further increase the thermostability at alkaline pH range via favorable charge-charge interactions between pm CA and solvent molecules. These findings may assist development of novel α-CAs with improved thermal and/or alkaline stability for applications such as CO capture and sequestration. PubMed: 31250619DOI: 10.14348/molcells.2019.0029 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (2 Å) |
Structure validation
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