1xby

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spinqualitylabelsall models 1xby, resolution 1.58Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image

Structure of 3-keto-L-gulonate 6-phosphate decarboxylase E112D/T169A mutant with bound D-ribulose 5-phosphate

Overview

3-Keto-L-gulonate 6-phosphate decarboxylase (KGPDC) and, D-arabino-hex-3-ulose 6-phosphate synthase (HPS), members of the orotidine, 5'-monophosphate decarboxylase (OMPDC) suprafamily, catalyze reactions, that involve the formation of Mg(2+)-ion stabilized 1,2-enediolate, intermediates. The active sites of KGPDC and HPS share several conserved, residues, including the presumed ligands for the Mg(2+) and a catalytic, histidine residue that has been implicated in protonation of the, intermediate in the KGPDC-catalyzed reaction. As reported in the previous, manuscript, both enzymes are naturally promiscuous, with KGPDC from, Escherichia coli catalyzing a low level of the HPS reaction and the HPS, from Methylomonas aminofaciens catalyzing a significant level of the KGPDC, reaction. Interestingly, the promiscuous HPS reaction catalyzed by KGPDC, can be significantly enhanced by replacing no more than four active site, residues from KGPDC reaction with residues from HPS. In this manuscript, we report structural studies of wild-type and mutant KDGPC's that provide, a structural explanation for both the natural promiscuity for the HPS, reaction and the enhanced HPS activity and diminished KGPDC activity, catalyzed by active site mutants.

About this Structure

1XBY is a Protein complex structure of sequences from Escherichia coli with 5RP and MG as ligands. Full crystallographic information is available from OCA.

Reference

Evolution of enzymatic activities in the orotidine 5'-monophosphate decarboxylase suprafamily: structural basis for catalytic promiscuity in wild-type and designed mutants of 3-keto-L-gulonate 6-phosphate decarboxylase., Wise EL, Yew WS, Akana J, Gerlt JA, Rayment I, Biochemistry. 2005 Feb 15;44(6):1816-23. PMID:15697207

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