1keq
From Proteopedia
Crystal Structure of F65A/Y131C Carbonic Anhydrase V, covalently modified with 4-chloromethylimidazole
Structural highlights
FunctionCAH5A_MOUSE Reversible hydration of carbon dioxide. Low activity. Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedThe crystal structure of F65A/Y131C murine alpha-carbonic anhydrase V (CAV), covalently modified at cysteine residues with 4-chloromethylimidazole, is reported at 1.88 A resolution. This modification introduces a methylimidazole (MI) group at residue C131 in the active site with important consequences. F65A/Y131C-MI CAV exhibits an up to 3-fold enhancement of catalytic activity over that of wild-type CAV [Earnhardt, J. N., Wright, S. K., Qian, M., Tu, C., Laipis, P. J., Viola, R. E., and Silverman, D. N. (1999) Arch. Biochem. Biophys. 361, 264-270]. In this modified CAV variant, C131-MI acts as a proton shuttle, facilitating the deprotonation of a zinc-bound water molecule to regenerate the nucleophilic zinc-bound hydroxide ion. A network of three hydrogen-bonded water molecules, across which proton transfer likely proceeds, bridges the zinc-bound water molecule and the C131-MI imidazole group. The structure of F65A/Y131C-MI CAV is compared to structures of Y64H/F65A murine CAV, wild-type human alpha-carbonic anhydrase II, and the gamma-carbonic anhydrase from Methanosarcina thermophilain an effort to outline common features of catalytic proton shuttles. Crystal structure of F65A/Y131C-methylimidazole carbonic anhydrase V reveals architectural features of an engineered proton shuttle.,Jude KM, Wright SK, Tu C, Silverman DN, Viola RE, Christianson DW Biochemistry. 2002 Feb 26;41(8):2485-91. PMID:11851394[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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