Plague Research Today is a free monthly online journal that collates and summarizes the latest research about Plague, including details on bubonic plague, yersinia pestis, infection, types, treatment.

Identification of critical amino acid residues in the plague biofilm Hms proteins.

Forman S, Bobrov AG, Kirillina O, Craig SK, Abney J, Fetherston JD, Perry RD

Department of Microbiology, Immunology, and Molecular Genetics, University of Kentucky, Lexington, KY 40536-0084, USA.

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.

Published 31 October 2006 in Microbiology, 152: 3399-410.
Full-text of this article is available online (may require subscription).

© 2005-2008 Plague Research Today. All Rights Reserved.