title: Identification of critical amino acid residues in the plague biofilm Hms proteins.
abstract: Yersinia pestis biofilm formation causes massive adsorption of haemin or Congo red in vitro as well as colonization and eventual blockage of the flea proventriculus in vivo. This blockage allows effective transmission of plague from some fleas, like the oriental rat flea, to mammals. Four Hms proteins, HmsH, HmsF, HmsR and HmsS, are essential for biofilm formation, with HmsT and HmsP acting as positive and negative regulators, respectively. HmsH has a beta-barrel structure with a large periplasmic domain while HmsF possesses polysaccharide deacetylase and COG1649 domains. HmsR is a putative glycosyltransferase while HmsS has no recognized domains. In this study, specific amino acids within conserved domains or within regions of high similarity in HmsH, HmsF, HmsR and HmsS proteins were selected for site-directed mutagenesis. Some but not all of the substitutions in HmsS and within the periplasmic domain of HmsH were critical for protein function. Substitutions within the glycosyltransferase domain of HmsR and the deacetylase domain of HmsF abolished biofilm formation in Y. pestis. Surprisingly, substitution of highly conserved residues within COG1649 did not affect HmsF function.
authors.affiliation: Department of Microbiology, Immunology, and Molecular Genetics, University of Kentucky, Lexington, Kentucky 40536-0084, USA.
authors.forename: Stanislav
authors.initials: S
authors.lastname: Forman
authors.affiliation: Department of Microbiology, Immunology, and Molecular Genetics, University of Kentucky, Lexington, Kentucky 40536-0084, USA.
authors.forename: Alexander G
authors.initials: AG
authors.lastname: Bobrov
authors.affiliation: Department of Microbiology, Immunology, and Molecular Genetics, University of Kentucky, Lexington, Kentucky 40536-0084, USA.
authors.forename: Olga
authors.initials: O
authors.lastname: Kirillina
authors.affiliation: Department of Microbiology, Immunology, and Molecular Genetics, University of Kentucky, Lexington, Kentucky 40536-0084, USA.
authors.forename: Susannah K
authors.initials: SK
authors.lastname: Craig
authors.affiliation: Department of Microbiology, Immunology, and Molecular Genetics, University of Kentucky, Lexington, Kentucky 40536-0084, USA.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Abney
authors.affiliation: Department of Microbiology, Immunology, and Molecular Genetics, University of Kentucky, Lexington, Kentucky 40536-0084, USA.
authors.forename: Jacqueline D
authors.initials: JD
authors.lastname: Fetherston
authors.affiliation: Department of Microbiology, Immunology, and Molecular Genetics, University of Kentucky, Lexington, Kentucky 40536-0084, USA.
authors.forename: Robert D
authors.initials: RD
authors.lastname: Perry
mesh_terms: D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D001426:Bacterial Proteins / Q000235:genetics*; D018441:Biofilms / Q000254:growth & development*; D016695:Glycosyltransferases / Q000235:genetics; D006427:Hemin / Q000378:metabolism; D008969:Molecular Sequence Data; D009876:Operon; D033903:Periplasmic Proteins / Q000235:genetics*; D010930:Plague; D017434:Protein Structure, Tertiary / Q000235:genetics / Q000502:physiology; D016415:Sequence Alignment; D015010:Yersinia pestis / Q000235:genetics / Q000378:metabolism / Q000502:physiology*
chemical_list: D001426:Bacterial Proteins; D033903:Periplasmic Proteins; D006427:Hemin; D016695:Glycosyltransferases