1dzr
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RMLC FROM SALMONELLA TYPHIMURIUM
OverviewOverview
Deoxythymidine diphosphate (dTDP)-L-rhamnose is the precursor of, L-rhamnose, a saccharide required for the virulence of some pathogenic, bacteria. dTDP-L-rhamnose is synthesized from glucose-1-phosphate and, deoxythymidine triphosphate (dTTP) via a pathway involving four distinct, enzymes. This pathway does not exist in humans and the enzymes involved in, dTDP-L-rhamnose synthesis are potential targets for the design of new, therapeutic agents. Here, the crystal structure of, dTDP-6-deoxy-D-xylo-4-hexulose 3,5 epimerase (RmlC, EC5.1.3.13) from, Salmonella enterica serovar Typhimurium was determined. The third enzyme, of the rhamnose biosynthetic pathway, RmlC epimerizes at two carbon, centers, the 3 and 5 positions of the sugar ring. The structure was, determined by multiwavelength anomalous diffraction to a resolution of, 2.17 A. RmlC is a dimer and each monomer is formed mainly from two, beta-sheets arranged in a beta-sandwich. The structure of a, dTDP-phenol-RmlC complex shows the substrate-binding site to be located, between the two beta-sheets; this site is formed from residues of both, monomers. Sequence alignments of other RmlC enzymes confirm that this, region is very highly conserved. The enzyme is distinct structurally from, other epimerases known and thus, is the first example of a new class of, carbohydrate epimerase.
About this StructureAbout this Structure
1DZR is a Single protein structure of sequence from Salmonella typhimurium with SO4 and GOL as ligands. Active as dTDP-4-dehydrorhamnose 3,5-epimerase, with EC number 5.1.3.13 Full crystallographic information is available from OCA.
ReferenceReference
RmlC, the third enzyme of dTDP-L-rhamnose pathway, is a new class of epimerase., Giraud MF, Leonard GA, Field RA, Berlind C, Naismith JH, Nat Struct Biol. 2000 May;7(5):398-402. PMID:10802738
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