1sb8

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spinqualitylabelsall models 1sb8, resolution 2.10Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image

Crystal structure of Pseudomonas aeruginosa UDP-N-acetylglucosamine 4-epimerase complexed with UDP-N-acetylgalactosamine

Overview

The O antigen of lipopolysaccharide in Gram-negative bacteria plays a, critical role in bacterium-host interactions, and for pathogenic bacteria, it is a major virulence factor. In Pseudomonas aeruginosa serotype O6 one, of the initial steps in O-antigen biosynthesis is catalyzed by a, saccharide epimerase, WbpP. WbpP is a member of the UDP-hexose 4-epimerase, family of enzymes and exists as a homo-dimer. This enzyme preferentially, catalyzes the conversion between UDP-GlcNAc and UDPGalNAc above UDP-Glc, and UDP-Gal, using NAD(+) as a cofactor. The crystal structures of WbpP in, complex with cofactor and either UDP-Glc or UDP-GalNAc were determined at, 2.5 and 2.1 A, respectively, which represents the first structural studies, of a genuine UDP-GlcNAc 4-epimerase. These structures in combination with, complementary mutagenesis studies suggest that the basis for the, differential substrate specificity of WbpP is a consequence of the, presence of a pliable solvent network in the active site. This information, allows for a comprehensive analysis of the relationship between sequence, and substrate specificity for UDP-hexose 4-epimerases and enables the, formulation of consensus sequences that predict substrate specificity of, UDP-hexose 4-epimerases yet to be biochemically characterized., Furthermore, the examination indicates that as little as one residue can, dictate substrate specificity. Nonetheless, phylogenetic analysis suggests, that this substrate specificity is an evolutionary and highly conserved, property within UDP-hexose 4-epimerases.

About this Structure

1SB8 is a Single protein structure of sequence from Pseudomonas aeruginosa with NAD and UD2 as ligands. Active as UDP-N-acetylglucosamine 4-epimerase, with EC number 5.1.3.7 Full crystallographic information is available from OCA.

Reference

Crystal structure of WbpP, a genuine UDP-N-acetylglucosamine 4-epimerase from Pseudomonas aeruginosa: substrate specificity in udp-hexose 4-epimerases., Ishiyama N, Creuzenet C, Lam JS, Berghuis AM, J Biol Chem. 2004 May 21;279(21):22635-42. Epub 2004 Mar 10. PMID:15016816

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