1e6b
From Proteopedia
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CRYSTAL STRUCTURE OF A ZETA CLASS GLUTATHIONE S-TRANSFERASE FROM ARABIDOPSIS THALIANA
Overview
The cis-trans isomerisation of maleylacetoacetate to fumarylacetoacetate, is the penultimate step in the tyrosine/phenylalanine catabolic pathway, and has recently been shown to be catalysed by glutathione S-transferase, enzymes belonging to the zeta class. Given this primary metabolic role it, is unsurprising that zeta class glutathione S-transferases are well, conserved over a considerable period of evolution, being found in, vertebrates, plants, insects and fungi. The structure of this glutathione, S-transferase, cloned from Arabidopsis thaliana, has been solved by single, isomorphous replacement with anomalous scattering and refined to a final, crystallographic R-factor of 19.6% using data from 25.0 A to 1.65 A. The, zeta class enzyme adopts the canonical glutathione S-transferase fold and, forms a homodimer with each subunit consisting of 221 residues. In, agreement with structures of glutathione S-transferases from the theta and, phi classes, a serine residue (Ser17) is present in the active site, at a, position that would allow it to stabilise the thiolate anion of, glutathione. Site-directed mutagenesis of this residue confirms its, importance in catalysis. In addition, the role of a highly conserved, cysteine residue (Cys19) present in the active site of the zeta class, glutathione S-transferase enzymes is discussed.
About this Structure
1E6B is a Single protein structure of sequence from Arabidopsis thaliana with BME as ligand. Active as Glutathione transferase, with EC number 2.5.1.18 Full crystallographic information is available from OCA.
Reference
The structure of a zeta class glutathione S-transferase from Arabidopsis thaliana: characterisation of a GST with novel active-site architecture and a putative role in tyrosine catabolism., Thom R, Dixon DP, Edwards R, Cole DJ, Lapthorn AJ, J Mol Biol. 2001 May 18;308(5):949-62. PMID:11352584
Page seeded by OCA on Tue Nov 20 13:47:53 2007
