1EKJ

THE X-RAY CRYSTALLOGRAPHIC STRUCTURE OF BETA CARBONIC ANHYDRASE FROM THE C3 DICOT PISUM SATIVUM

Summary for 1EKJ

• Entry DOI: 10.2210/pdb1ekj/pdb
• Descriptor: BETA-CARBONIC ANHYDRASE, ACETATE ION, AZIDE ION, ... (9 entities in total)
• Functional Keywords: rossman fold domain, strand exchange, lyase
• Biological source: Pisum sativum (pea)
• Total number of polymer chains: 8
• Total formula weight: 193939.28

Authors

Kimber, M.S.,Pai, E.F. (deposition date: 2000-03-08, release date: 2000-06-07, Last modification date: 2024-02-07)

Primary citation

Kimber, M.S.,Pai, E.F.
The active site architecture of Pisum sativum beta-carbonic anhydrase is a mirror image of that of alpha-carbonic anhydrases.
EMBO J., 19:1407-1418, 2000

PubMed Abstract: We have determined the structure of the beta-carbonic anhydrase from the dicotyledonous plant Pisum sativum at 1.93 A resolution, using a combination of multiple anomalous scattering off the active site zinc ion and non-crystallographic symmetry averaging. The mol- ecule assembles as an octamer with a novel dimer of dimers of dimers arrangement. Two distinct patterns of conservation of active site residues are observed, implying two potentially mechanistically distinct classes of beta-carbonic anhydrases. The active site is located at the interface between two monomers, with Cys160, His220 and Cys223 binding the catalytic zinc ion and residues Asp162 (oriented by Arg164), Gly224, Gln151, Val184, Phe179 and Tyr205 interacting with the substrate analogue, acetic acid. The substrate binding groups have a one to one correspondence with the functional groups in the alpha-carbonic anhydrase active site, with the corresponding residues being closely superimposable by a mirror plane. Therefore, despite differing folds, alpha- and beta-carbonic anhydrase have converged upon a very similar active site design and are likely to share a common mechanism.

PubMed: 10747009
DOI: 10.1093/emboj/19.7.1407

Experimental method

X-RAY DIFFRACTION (1.93 Å)