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1keq
From Proteopedia
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'''Crystal Structure of F65A/Y131C Carbonic Anhydrase V, covalently modified with 4-chloromethylimidazole''' | '''Crystal Structure of F65A/Y131C Carbonic Anhydrase V, covalently modified with 4-chloromethylimidazole''' | ||
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[[Category: Viola, R E.]] | [[Category: Viola, R E.]] | ||
[[Category: Wright, S K.]] | [[Category: Wright, S K.]] | ||
| - | [[Category: | + | [[Category: Engineered residue]] |
| - | [[Category: | + | [[Category: Proton transfer]] |
| - | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Fri May 2 22:39:11 2008'' | |
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | |
Revision as of 19:39, 2 May 2008
Crystal Structure of F65A/Y131C Carbonic Anhydrase V, covalently modified with 4-chloromethylimidazole
Overview
The 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.
About this Structure
1KEQ is a Single protein structure of sequence from Mus musculus. Full crystallographic information is available from OCA.
Reference
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 Page seeded by OCA on Fri May 2 22:39:11 2008
