title: An O-antigen processing function for Wzx (RfbX): a promising candidate for O-unit flippase.
abstract: O antigen is the major cell surface antigen of gram-negative bacteria, and the genes responsible for its synthesis are located in a single gene cluster. The wzx (rbfX) gene, which is characteristic of the major class of O-antigen gene clusters, encodes a hydrophobic protein with 12 potential transmembrane segments. We demonstrate that a wzx mutant accumulates undecaprenol pyrophosphate-linked O units which appear to be on the cytoplasmic side of the cytoplasmic membrane, suggesting that the wzx gene encodes a flippase for O-unit translocation across that membrane.
authors.affiliation: Department of Microbiology, University of Sydney, New South Wales, Australia.
authors.forename: D
authors.initials: D
authors.lastname: Liu
authors.forename: R A
authors.initials: RA
authors.lastname: Cole
authors.forename: P R
authors.initials: PR
authors.lastname: Reeves
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D002240:Carbohydrate Sequence; D002352:Carrier Proteins / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D026901:Membrane Transport Proteins; D008969:Molecular Sequence Data; D005810:Multigene Family; D009154:Mutation; D019081:O Antigens / Q000096:biosynthesis*; D049294:Phospholipid Transfer Proteins
chemical_list: D001426:Bacterial Proteins; D002352:Carrier Proteins; D008565:Membrane Proteins; D026901:Membrane Transport Proteins; D019081:O Antigens; D049294:Phospholipid Transfer Proteins; C092801:RfbX protein, Shigella flexneri