1zco
From Proteopedia
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Crystal structure of pyrococcus furiosus 3-deoxy-D-arabino-heptulosonate 7-phosphate synthase
Overview
3-deoxy-D-arabino-heptulosonate-7-phosphate synthase (DAH7PS) catalyzes, the condensation reaction between phosphoenolpyruvate (PEP) and the, four-carbon monosaccharide D-erythrose 4-phosphate (E4P). DAH7PS from the, hyperthermophile Pyrococcus furiosus is a member of the DAH7PS Ibeta, subfamily, which also includes the KDO8PS enzymes. KDO8PS, (3-deoxy-D-manno-octulosonate-8-phosphate synthase) catalyzes a closely, related reaction of PEP with the five-carbon monosaccharide D-arabinose, 5-phosphate (A5P). DAH7PS from P. furiosus requires a metal ion for, activity and, unlike other characterized DAH7PS enzymes, is not inhibited, by aromatic amino acids. Purified P. furiosus DAH7PS is able to utilize, not only the four-carbon phosphorylated monosaccharides E4P and, 2-deoxy-D-erythrose 4-phosphate but also the five-carbon phosphorylated, monosaccharides A5P, D-ribose 5-phosphate, and 2-deoxy-D-ribose, 5-phosphate with similar kcat but much increased KM values., DL-glyceraldehyde 3-phosphate and D-glucose 6-phosphate are not, substrates. The structure of recombinant P. furiosus DAH7PS in complex, with PEP was determined to 2.25 A resolution. The asymmetric unit consists, of a dimer of (beta/alpha)8-barrel subunits. Analysis of the buried, surfaces formed by dimerization and tetramerization, as observed in the, crystal structure, provides insight into both the oligomeric status in, solution and the substrate ambiguity of P. furiosus DAH7PS. P. furiosus, DAH7PS is both the first archaeal and the first "naked" DAH7PS (without, N-terminal extensions) to be fully characterized functionally and, structurally. The broad substrate specificity of this DAH7PS, the lack of, allosteric inhibition, and various structural features indicate that, of, the enzymes characterized to date, P. furiosus DAH7PS may be the, contemporary protein closest to the ancestral type I enzyme.
About this Structure
1ZCO is a Single protein structure of sequence from Pyrococcus furiosus with CL, MN and PEP as ligands. Active as 3-deoxy-7-phosphoheptulonate synthase, with EC number 2.5.1.54 Full crystallographic information is available from OCA.
Reference
Substrate ambiguity and crystal structure of Pyrococcus furiosus 3-deoxy-D-arabino-heptulosonate-7-phosphate synthase: an ancestral 3-deoxyald-2-ulosonate-phosphate synthase?, Schofield LR, Anderson BF, Patchett ML, Norris GE, Jameson GB, Parker EJ, Biochemistry. 2005 Sep 13;44(36):11950-62. PMID:16142893
Page seeded by OCA on Sun Nov 25 04:49:28 2007
