tailieunhanh - Báo cáo khoa học: The structural basis for catalytic function of GMD and RMD, two closely related enzymes from the GDP-D-rhamnose biosynthesis pathway

The rare 6-deoxysugard-rhamnose is a component of bacterial cell sur-face glycans, including the d-rhamnose homopolymer produced by Pseu-domonas aeruginosa, called A-band O polysaccharide. GDP-d-rhamnose synthesis from GDP-d-mannose is catalyzed by two enzymes. The first is a GDP-d-mannose-4,6-dehydratase (GMD). The second enzyme, RMD, reduces the GMD product (GDP-6-deoxy-d-lyxo-hexos-4-ulose) to GDP-d-rhamnose. | The structural basis for catalytic function of GMD and RMD two closely related enzymes from the GDP-D-rhamnose biosynthesis pathway Iprrv D Ki nn 1 K 51 0n K H Pnnn1 Ỷ Ạ A phh2 Frin l l n H r r .o n1 r o ifl I l lpN551l 3 Ỷ eiiy . I ly đicH . . UUH Uulc . e IIII . neison av . cay 1 Jean-Robert Brisson3 Paul Messner4 R. M. Garavito2 and Joseph S. Lam1 1 Department of Molecular and Cellular Biology University of Guelph Canada 2 Department of Biochemistry and Molecular Biology Michigan State University East Lansing MI USA 3 Institute for BiologicalSciences NationalResearch Council Ottawa Canada 4 Zentrum fur NanoBiotechnologie Universitat fur Bodenkultur Wien Austria Keywords Aneurinibacillus thermoaerophilus D-rhamnose GMD RMD Pseudomonas aeruginosa real-time NMR Correspondence J. S. Lam Department of Molecular and Cellular Biology University of Guelph Ontario N1G 2W1 Canada Fax 1 519 837 1802 Tel 1 519 824 4120 extension 53823 E-mail jlam@ Present address fDepartment of Physiology and Biophysics University of Calgary Canada ỊDepartment of Chemistry University of Toronto Canada Database Protein structure model data are available in the Protein Data Bank database under the accession number 2PK3 These authors contributed equally to this work Received 26 November 2008 revised 28 February 2009 accepted 4 March 2009 doi The rare 6-deoxysugar D-rhamnose is a component of bacterial cell surface glycans including the D-rhamnose homopolymer produced by Pseudomonas aeruginosa called A-band O polysaccharide. GDP-D-rhamnose synthesis from GDP-D-mannose is catalyzed by two enzymes. The first is a GDP-D-mannose-4 6-dehydratase GMD . The second enzyme RMD reduces the GMD product GDP-6-deoxy-D-lyxo-hexos-4-ulose to GDP-D-rhamnose. Genes encoding GMD and RMD are present in P. aeruginosa and genetic evidence indicates they act in A-band O-polysaccharide biosynthesis. Details of their enzyme functions have not however been previously .