1keq
From Proteopedia
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| , resolution 1.88Å | |||||||
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| Ligands: | , , , | ||||||
| Gene: | MCA5C (Mus musculus) | ||||||
| Activity: | Carbonate dehydratase, with EC number 4.2.1.1 | ||||||
| Related: | 1DMX
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| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
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 Sun Mar 30 21:47:31 2008
