1ekj
From Proteopedia
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THE X-RAY CRYSTALLOGRAPHIC STRUCTURE OF BETA CARBONIC ANHYDRASE FROM THE C3 DICOT PISUM SATIVUM
Overview
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.
About this Structure
1EKJ is a Single protein structure of sequence from Pisum sativum with ACT, AZI, ZN, CU, CL, CIT and EDO as ligands. Active as Carbonate dehydratase, with EC number 4.2.1.1 Full crystallographic information is available from OCA.
Reference
The active site architecture of Pisum sativum beta-carbonic anhydrase is a mirror image of that of alpha-carbonic anhydrases., Kimber MS, Pai EF, EMBO J. 2000 Apr 3;19(7):1407-18. PMID:10747009
Page seeded by OCA on Tue Nov 20 14:04:53 2007
Categories: Carbonate dehydratase | Pisum sativum | Single protein | Kimber, M.S. | Pai, E.F. | ACT | AZI | CIT | CL | CU | EDO | ZN | Rossman fold domain | Strand exchange
