2h1h
E. coli heptosyltransferase WaaC with ADP-2-deoxy-2-fluoro heptose
Structural highlights
FunctionRFAC_ECOLI Heptose transfer to the lipopolysaccharide core. It transfers the innermost heptose to [4'-P](3-deoxy-D-manno-octulosonic acid)2-IVA. Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedLipopolysaccharides constitute the outer leaflet of the outer membrane of Gram-negative bacteria and are therefore essential for cell growth and viability. The heptosyltransferase WaaC is a glycosyltransferase (GT) involved in the synthesis of the inner core region of LPS. It catalyzes the addition of the first L-glycero-D-manno-heptose (heptose) molecule to one 3-deoxy-D-manno-oct-2-ulosonic acid (Kdo) residue of the Kdo2-lipid A molecule. Heptose is an essential component of the LPS core domain; its absence results in a truncated lipopolysaccharide associated with the deep-rough phenotype causing a greater susceptibility to antibiotic and an attenuated virulence for pathogenic Gram-negative bacteria. Thus, WaaC represents a promising target in antibacterial drug design. Here, we report the structure of WaaC from the Escherichia coli pathogenic strain RS218 alone at 1.9 A resolution, and in complex with either ADP or the non-cleavable analog ADP-2-deoxy-2-fluoro-heptose of the sugar donor at 2.4 A resolution. WaaC adopts the GT-B fold in two domains, characteristic of one glycosyltransferase structural superfamily. The comparison of the three different structures shows that WaaC does not undergo a domain rotation, characteristic of the GT-B family, upon substrate binding, but allows the substrate analog and the reaction product to adopt remarkably distinct conformations inside the active site. In addition, both binary complexes offer a close view of the donor subsite and, together with results from site-directed mutagenesis studies, provide evidence for a model of the catalytic mechanism. Structure of the Escherichia coli heptosyltransferase WaaC: binary complexes with ADP and ADP-2-deoxy-2-fluoro heptose.,Grizot S, Salem M, Vongsouthi V, Durand L, Moreau F, Dohi H, Vincent S, Escaich S, Ducruix A J Mol Biol. 2006 Oct 20;363(2):383-94. Epub 2006 Jul 29. PMID:16963083[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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