1y3t
From Proteopedia
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Crystal structure of YxaG, a dioxygenase from Bacillus subtilis
Overview
Common structural motifs, such as the cupin domains, are found in enzymes, performing different biochemical functions while retaining a similar, active site configuration and structural scaffold. The soil bacterium, Bacillus subtilis has 20 cupin genes (0.5% of the total genome) with up to, 14% of its genes in the form of doublets, thus making it an attractive, system for studying the effects of gene duplication. There are four, bicupins in B. subtilis encoded by the genes yvrK, yoaN, yxaG, and ywfC., The gene products of yvrK and yoaN function as oxalate decarboxylases with, a manganese ion at the active site(s), whereas YwfC is a bacitracin, synthetase. Here we present the crystal structure of YxaG, a novel, iron-containing quercetin 2,3-dioxygenase with one active site in each, cupin domain. Yxag is a dimer, both in solution and in the crystal. The, crystal structure shows that the coordination geometry of the Fe ion is, different in the two active sites of YxaG. Replacement of the iron at the, active site with other metal ions suggests modulation of enzymatic, activity in accordance with the Irving-Williams observation on the, stability of metal ion complexes. This observation, along with a, comparison with the crystal structure of YvrK determined recently, has, allowed for a detailed structure-function analysis of the active site, providing clues to the diversification of function in the bicupin family, of proteins.
About this Structure
1Y3T is a Single protein structure of sequence from Bacillus subtilis with FE as ligand. Full crystallographic information is available from OCA.
Reference
The crystal structure of a quercetin 2,3-dioxygenase from Bacillus subtilis suggests modulation of enzyme activity by a change in the metal ion at the active site(s)., Gopal B, Madan LL, Betz SF, Kossiakoff AA, Biochemistry. 2005 Jan 11;44(1):193-201. PMID:15628860
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