1ylh
Crystal Structure of Phosphoenolpyruvate Carboxykinase from Actinobaccilus succinogenes in Complex with Manganese and Pyruvate
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OverviewOverview
Actinobacillus succinogenes can produce, via fermentation, high, concentrations of succinate, an important industrial commodity. A key, enzyme in this pathway is phosphoenolpyruvate carboxykinase (PCK), which, catalyzes the production of oxaloacetate from phosphoenolpyruvate and, carbon dioxide, with the concomitant conversion of adenosine, 5'-diphosphate to adenosine 5'-triphosphate. 1.85 and 1.70 A resolution, structures of the native and a pyruvate/Mn(2+)/phosphate complex have been, solved, respectively. The structure of the complex contains sulfhydryl, reducing agents covalently bound to three cysteine residues via disulfide, bonds. One of these cysteine residues (Cys285) is located in the, active-site cleft and may be analogous to the putative reactive cysteine, of PCK from Trypanosoma cruzi. Cys285 is also part of a previously, unreported conserved motif comprising residues 280-287 and containing the, pattern NXEXGXY(/F)A(/G); this new motif appears to have a structural role, in stabilizing and positioning side chains that bind substrates and metal, ions. The first few residues of this motif connect the two domains of the, enzyme and a fulcrum point appears to be located near Asn280. In addition, an active-site Asp residue forms two coordinate bonds with the Mn(2+) ion, present in the structure of the complex in a symmetrical bidentate manner, unlike in other PCK structures that contain a manganese ion.
About this StructureAbout this Structure
1YLH is a Single protein structure of sequence from Actinobacillus succinogenes with MN, PO4, DT3, BME, PYR and FMT as ligands. Active as Phosphoenolpyruvate carboxykinase (ATP), with EC number 4.1.1.49 Full crystallographic information is available from OCA.
ReferenceReference
Structure of PEP carboxykinase from the succinate-producing Actinobacillus succinogenes: a new conserved active-site motif., Leduc YA, Prasad L, Laivenieks M, Zeikus JG, Delbaere LT, Acta Crystallogr D Biol Crystallogr. 2005 Jul;61(Pt 7):903-12. Epub 2005, Jun 24. PMID:15983413
Page seeded by OCA on Sun Nov 25 04:16:47 2007