1i6p
CRYSTAL STRUCTURE OF E. COLI BETA CARBONIC ANHYDRASE (ECCA)CRYSTAL STRUCTURE OF E. COLI BETA CARBONIC ANHYDRASE (ECCA)
Structural highlights
FunctionEvolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedCarbonic anhydrases fall into three distinct evolutionary and structural classes: alpha, beta, and gamma. The beta-class carbonic anhydrases (beta-CAs) are widely distributed among higher plants, simple eukaryotes, eubacteria, and archaea. We have determined the crystal structure of ECCA, a beta-CA from Escherichia coli, to a resolution of 2.0 A. In agreement with the structure of the beta-CA from the chloroplast of the red alga Porphyridium purpureum, the active-site zinc in ECCA is tetrahedrally coordinated by the side chains of four conserved residues. These results confirm the observation of a unique pattern of zinc ligation in at least some beta-CAS: The absence of a water molecule in the inner coordination sphere is inconsistent with known mechanisms of CA activity. ECCA activity is highly pH-dependent in the physiological range, and its expression in yeast complements an oxygen-sensitive phenotype displayed by a beta-CA-deletion strain. The structural and biochemical characterizations of ECCA presented here and the comparisons with other beta-CA structures suggest that ECCA can adopt two distinct conformations displaying widely divergent catalytic rates. Crystal structure of E. coli beta-carbonic anhydrase, an enzyme with an unusual pH-dependent activity.,Cronk JD, Endrizzi JA, Cronk MR, O'neill JW, Zhang KY Protein Sci. 2001 May;10(5):911-22. PMID:11316870[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences |
| ||||||||||||||||||