2e0x
From Proteopedia
OCA (Talk | contribs)
(New page: 200px<br /><applet load="2e0x" size="450" color="white" frame="true" align="right" spinBox="true" caption="2e0x, resolution 1.950Å" /> '''Crystal Structure o...)
Next diff →
Revision as of 07:46, 21 November 2007
|
Crystal Structure of Gamma-glutamyltranspeptidase from Escherichia coli (monoclinic form)
Overview
Gamma-glutamyltranspeptidase (GGT) is a heterodimic enzyme that is, generated from the precursor protein through posttranslational processing, and catalyzes the hydrolysis of gamma-glutamyl bonds in gamma-glutamyl, compounds such as glutathione and/or the transfer of the gamma-glutamyl, group to other amino acids and peptides. We have determined the crystal, structure of GGT from Escherichia coli K-12 at 1.95 A resolution. GGT has, a stacked alphabetabetaalpha fold comprising the large and small subunits, similar to the folds seen in members of the N-terminal nucleophile, hydrolase superfamily. The active site Thr-391, the N-terminal residue of, the small subunit, is located in the groove, from which the pocket for, gamma-glutamyl moiety binding follows. We have further determined the, structure of the gamma-glutamyl-enzyme intermediate trapped by flash, cooling the GGT crystal soaked in glutathione solution and the structure, of GGT in complex with l-glutamate. These structures revealed how the, gamma-glutamyl moiety and l-glutamate are recognized by the enzyme. A, water molecule was seen on the carbonyl carbon of the, gamma-glutamyl-Thr-391 Ogamma bond in the intermediate that is to be, hydrolyzed. Notably the residues essential for GGT activity (Arg-114, Asp-433, Ser-462, and Ser-463 in E. coli GGT) shown by site-directed, mutagenesis of human GGT are all involved in the binding of the, gamma-glutamyl moiety. The structure of E. coli GGT presented here, together with sequence alignment of GGTs, may be applicable to interpret, the biochemical and genetic data of other GGTs.
About this Structure
2E0X is a Protein complex structure of sequences from Escherichia coli with CA as ligand. Active as Gamma-glutamyltransferase, with EC number 2.3.2.2 Full crystallographic information is available from OCA.
Reference
Crystal structures of gamma-glutamyltranspeptidase from Escherichia coli, a key enzyme in glutathione metabolism, and its reaction intermediate., Okada T, Suzuki H, Wada K, Kumagai H, Fukuyama K, Proc Natl Acad Sci U S A. 2006 Apr 25;103(17):6471-6. Epub 2006 Apr 17. PMID:16618936
Page seeded by OCA on Wed Nov 21 09:54:02 2007
