title: Staphylococcus intermedius produces a functional agr autoinducing peptide containing a cyclic lactone.
abstract: The agr system is a global regulator of accessory functions in staphylococci, including genes encoding exoproteins involved in virulence. The agr locus contains a two-component signal transduction module that is activated by an autoinducing peptide (AIP) encoded within the agr locus and is conserved throughout the genus. The AIP has an unusual partially cyclic structure that is essential for function and that, in all but one case, involves an internal thiolactone bond between a conserved cysteine and the C-terminal carboxyl group. The exceptional case is a strain of Staphylococcus intermedius that has a serine in place of the conserved cysteine. We demonstrate here that the S. intermedius AIP is processed by the S. intermedius AgrB protein to generate a cyclic lactone, that it is an autoinducer as well as a cross-inhibitor, and that all of five other S. intermedius strains examined also produce serine-containing AIPs.
authors.affiliation: Departments of Microbiology and Immunology, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA. gji@usuhs.mil
authors.forename: Guangyong
authors.initials: G
authors.lastname: Ji
authors.forename: Wuhong
authors.initials: W
authors.lastname: Pei
authors.forename: Linsheng
authors.initials: L
authors.lastname: Zhang
authors.forename: Rongde
authors.initials: R
authors.lastname: Qiu
authors.forename: Jianqun
authors.initials: J
authors.lastname: Lin
authors.forename: Yvonne
authors.initials: Y
authors.lastname: Benito
authors.forename: Gerard
authors.initials: G
authors.lastname: Lina
authors.forename: Richard P
authors.initials: RP
authors.lastname: Novick
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics / Q000502:physiology*; D004269:DNA, Bacterial / Q000302:isolation & purification; D015964:Gene Expression Regulation, Bacterial; D006460:Hemolysin Proteins / Q000096:biosynthesis / Q000378:metabolism; D006461:Hemolysis / Q000235:genetics / Q000502:physiology; D007783:Lactones / Q000032:analysis* / Q000737:chemistry; D008969:Molecular Sequence Data; D009154:Mutation; D010456:Peptides, Cyclic; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D012694:Serine / Q000378:metabolism; D013210:Staphylococcus / Q000235:genetics / Q000378:metabolism*
chemical_list: C414532:AgrD protein, Staphylococcus; D001426:Bacterial Proteins; D004269:DNA, Bacterial; D006460:Hemolysin Proteins; D007783:Lactones; D010456:Peptides, Cyclic; D012694:Serine