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PDBsum entry 1keq

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Lyase PDB id
1keq
Jmol
Contents
Protein chains
238 a.a. *
Ligands
4MZ ×5
ACY ×3
Metals
__K
_ZN ×2
Waters ×471
* Residue conservation analysis

References listed in PDB file
Key reference
Title Crystal structure of f65a/y131c-Methylimidazole carbonic anhydrase V reveals architectural features of an engineered proton shuttle.
Authors K.M.Jude, S.K.Wright, C.Tu, D.N.Silverman, R.E.Viola, D.W.Christianson.
Ref. Biochemistry, 2002, 41, 2485-2491. [DOI no: 10.1021/bi015808q]
PubMed id 11851394
Abstract
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.
Secondary reference #1
Title Introduction of histidine analogs leads to enhanced proton transfer in carbonic anhydrase V.
Authors J.N.Earnhardt, S.K.Wright, M.Qian, C.Tu, P.J.Laipis, R.E.Viola, D.N.Silverman.
Ref. Arch Biochem Biophys, 1999, 361, 264-270. [DOI no: 10.1006/abbi.1998.0984]
PubMed id 9882455
Full text Abstract
Secondary reference #2
Title Structure determination of murine mitochondrial carbonic anhydrase V at 2.45-A resolution: implications for catalytic proton transfer and inhibitor design.
Authors P.A.Boriack-Sjodin, R.W.Heck, P.J.Laipis, D.N.Silverman, D.W.Christianson.
Ref. Proc Natl Acad Sci U S A, 1995, 92, 10949-10953. [DOI no: 10.1073/pnas.92.24.10949]
PubMed id 7479916
Full text Abstract
PROCHECK
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