title: Substrate specificity of the AmpG permease required for recycling of cell wall anhydro-muropeptides.
abstract: AmpG was originally identified as a gene required for induction of beta-lactamase. Subsequently, we found AmpG to be a permease required for recycling of murein tripeptide and uptake of anhydro-muropeptides. We have now studied the specificity of the AmpG permease. The principal requirement is for the presence of the disaccharide, N-acetylglucosaminyl-beta-1,4-anhydro-N-acetylmuramic acid (GlcNAc-anhMurNAc). These unique substrates for AmpG, which contain murein peptides linked to GlcNAc-anhMurNAc, are produced by turnover of the cell wall during logarithmic growth. AmpG permease is sensitive to carbonylcyanide m-chlorophenylhydrazone, demonstrating that AmpG permease is a single-component permease and that transport is dependent on the proton motive force.
authors.affiliation: Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts 02111, USA.
authors.forename: Qiaomei
authors.initials: Q
authors.lastname: Cheng
authors.forename: James T
authors.initials: JT
authors.lastname: Park
mesh_terms: D001426:Bacterial Proteins / Q000378:metabolism*; D001431:Bacteriological Techniques; D002473:Cell Wall; D004926:Escherichia coli / Q000201:enzymology* / Q000254:growth & development; D005615:Freezing; D005944:Glucosamine / Q000378:metabolism; D008565:Membrane Proteins / Q000378:metabolism*; D026901:Membrane Transport Proteins; D009112:Muramic Acids / Q000737:chemistry / Q000378:metabolism; D010455:Peptides / Q000378:metabolism; D010457:Peptidoglycan / Q000378:metabolism; D013379:Substrate Specificity; D014316:Tritium / Q000378:metabolism
chemical_list: C084284:AmpG protein, Bacteria; D001426:Bacterial Proteins; D008565:Membrane Proteins; D026901:Membrane Transport Proteins; D009112:Muramic Acids; D010455:Peptides; D010457:Peptidoglycan; D014316:Tritium; D005944:Glucosamine