Identification of critical amino acid residues in the plague biofilm Hms proteins.
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.
Forman
Stanislav
S
Department of Microbiology, Immunology, and Molecular Genetics, University of Kentucky, Lexington, Kentucky 40536-0084, USA.
Bobrov
Alexander G
AG
Department of Microbiology, Immunology, and Molecular Genetics, University of Kentucky, Lexington, Kentucky 40536-0084, USA.
Kirillina
Olga
O
Department of Microbiology, Immunology, and Molecular Genetics, University of Kentucky, Lexington, Kentucky 40536-0084, USA.
Craig
Susannah K
SK
Department of Microbiology, Immunology, and Molecular Genetics, University of Kentucky, Lexington, Kentucky 40536-0084, USA.
Abney
Jennifer
J
Department of Microbiology, Immunology, and Molecular Genetics, University of Kentucky, Lexington, Kentucky 40536-0084, USA.
Fetherston
Jacqueline D
JD
Department of Microbiology, Immunology, and Molecular Genetics, University of Kentucky, Lexington, Kentucky 40536-0084, USA.
Perry
Robert D
RD
Department of Microbiology, Immunology, and Molecular Genetics, University of Kentucky, Lexington, Kentucky 40536-0084, USA.
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*
D001426:Bacterial Proteins; D033903:Periplasmic Proteins; D006427:Hemin; D016695:Glycosyltransferases