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