1XBY

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

Summary for 1XBY

• Entry DOI: 10.2210/pdb1xby/pdb
• Related: 1XBV 1XBX 1XBZ
• Descriptor: 3-keto-L-gulonate 6-phosphate decarboxylase, RIBULOSE-5-PHOSPHATE, MAGNESIUM ION, ... (4 entities in total)
• Functional Keywords: tim barrel, unknown function
• Biological source: Escherichia coli
• Total number of polymer chains: 2
• Total formula weight: 47626.80

Authors

Wise, E.L.,Yew, W.S.,Akana, J.,Gerlt, J.A.,Rayment, I. (deposition date: 2004-08-31, release date: 2005-04-26, Last modification date: 2024-02-14)

Primary citation

Wise, E.L.,Yew, W.S.,Akana, J.,Gerlt, J.A.,Rayment, I.
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
Biochemistry, 44:1816-1823, 2005

PubMed Abstract: 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.

PubMed: 15697207
DOI: 10.1021/bi0478143

Experimental method

X-RAY DIFFRACTION (1.58 Å)