1i8t
From Proteopedia
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STRCUTURE OF UDP-GALACTOPYRANOSE MUTASE FROM E.COLI
Overview
Uridine diphosphogalactofuranose (UDP-Galf ) is the precursor of the, d-galactofuranose (Galf ) residues found in bacterial and parasitic cell, walls, including those of many pathogens, such as Mycobacterium, tuberculosis and Trypanosoma cruzi. UDP-Galf is made from, UDP-galactopyranose (UDP-Galp) by the enzyme UDP-galactopyranose mutase, (mutase). The mutase enzyme is essential for the viability of mycobacteria, and is not found in humans, making it a viable therapeutic target. The, mechanism by which mutase achieves the unprecedented ring contraction of a, nonreducing sugar is unclear. We have solved the crystal structure of, Escherichia coli mutase to 2.4 A resolution. The novel structure shows, that the flavin nucleotide is located in a cleft lined with conserved, residues. Site-directed mutagenesis studies indicate that this cleft, contains the active site, with the sugar ring of the substrate, UDP-galactose adjacent to the exposed isoalloxazine ring of FAD. Assay, results establish that the enzyme is active only when flavin is reduced., We conclude that mutase most likely functions by transient reduction of, substrate.
About this Structure
1I8T is a Single protein structure of sequence from Escherichia coli with FAD as ligand. Active as UDP-galactopyranose mutase, with EC number 5.4.99.9 Full crystallographic information is available from OCA.
Reference
UDP-galactopyranose mutase has a novel structure and mechanism., Sanders DA, Staines AG, McMahon SA, McNeil MR, Whitfield C, Naismith JH, Nat Struct Biol. 2001 Oct;8(10):858-63. PMID:11573090
Page seeded by OCA on Tue Nov 20 17:09:46 2007
