1keq
From Proteopedia
(New page: 200px<br /><applet load="1keq" size="450" color="white" frame="true" align="right" spinBox="true" caption="1keq, resolution 1.88Å" /> '''Crystal Structure of...) |
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| - | [[Image:1keq.jpg|left|200px]]<br /><applet load="1keq" size=" | + | [[Image:1keq.jpg|left|200px]]<br /><applet load="1keq" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1keq, resolution 1.88Å" /> | caption="1keq, resolution 1.88Å" /> | ||
'''Crystal Structure of F65A/Y131C Carbonic Anhydrase V, covalently modified with 4-chloromethylimidazole'''<br /> | '''Crystal Structure of F65A/Y131C Carbonic Anhydrase V, covalently modified with 4-chloromethylimidazole'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The crystal structure of F65A/Y131C murine alpha-carbonic anhydrase V | + | 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== | ==About this Structure== | ||
| - | 1KEQ is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Mus_musculus Mus musculus] with K, ZN, 4MZ and ACY as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Carbonate_dehydratase Carbonate dehydratase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=4.2.1.1 4.2.1.1] Full crystallographic information is available from [http:// | + | 1KEQ is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Mus_musculus Mus musculus] with <scene name='pdbligand=K:'>K</scene>, <scene name='pdbligand=ZN:'>ZN</scene>, <scene name='pdbligand=4MZ:'>4MZ</scene> and <scene name='pdbligand=ACY:'>ACY</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Carbonate_dehydratase Carbonate dehydratase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=4.2.1.1 4.2.1.1] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1KEQ OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Mus musculus]] | [[Category: Mus musculus]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Christianson, D | + | [[Category: Christianson, D W.]] |
| - | [[Category: Jude, K | + | [[Category: Jude, K M.]] |
| - | [[Category: Silverman, D | + | [[Category: Silverman, D N.]] |
[[Category: Tu, C.]] | [[Category: Tu, C.]] | ||
| - | [[Category: Viola, R | + | [[Category: Viola, R E.]] |
| - | [[Category: Wright, S | + | [[Category: Wright, S K.]] |
[[Category: 4MZ]] | [[Category: 4MZ]] | ||
[[Category: ACY]] | [[Category: ACY]] | ||
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[[Category: proton transfer]] | [[Category: proton transfer]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 13:33:17 2008'' |
Revision as of 11:33, 21 February 2008
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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 with , , and as ligands. Active as Carbonate dehydratase, with EC number 4.2.1.1 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 Thu Feb 21 13:33:17 2008
Categories: Carbonate dehydratase | Mus musculus | Single protein | Christianson, D W. | Jude, K M. | Silverman, D N. | Tu, C. | Viola, R E. | Wright, S K. | 4MZ | ACY | K | ZN | Engineered residue | Proton transfer
