title: Identification of the Bacillus anthracis (gamma) phage receptor.
abstract: Bacillus anthracis, a gram-positive, spore-forming bacterium, is the etiological agent of anthrax. It belongs to the Bacillus cereus group, which also contains Bacillus cereus and Bacillus thuringiensis. Most B. anthracis strains are sensitive to phage gamma, but most B. cereus and B. thuringiensis strains are resistant to the lytic action of phage gamma. Here, we report the identification of a protein involved in the bacterial receptor for the gamma phage, which we term GamR (Gamma phage receptor). It is an LPXTG protein (BA3367, BAS3121) and is anchored by the sortase A. A B. anthracis sortase A mutant is not as sensitive as the parental strain nor as the sortase B and sortase C mutants, whereas the GamR mutant is resistant to the lytic action of the phage. Electron microscopy reveals the binding of the phage to the surface of the parental strain and its absence from the GamR mutant. Spontaneous B. anthracis mutants resistant to the phage harbor mutations in the gene encoding the GamR protein. A B. cereus strain that is sensitive to the phage possesses a protein similar (89% identity) to GamR. B. thuringiensis 97-27, a strain which, by sequence analysis, is predicted to harbor a GamR-like protein, is resistant to the phage but nevertheless displays phage binding.
authors.affiliation: Toxines et Pathogénie Bactérienne, Institut Pasteur, 28 Rue du Dr. Roux, cedex 15, Paris 75724, France.
authors.forename: Sophie
authors.initials: S
authors.lastname: Davison
authors.forename: Evelyne
authors.initials: E
authors.lastname: Couture-Tosi
authors.forename: Thomas
authors.initials: T
authors.lastname: Candela
authors.forename: Michèle
authors.initials: M
authors.lastname: Mock
authors.forename: Agnès
authors.initials: A
authors.lastname: Fouet
mesh_terms: D000595:Amino Acid Sequence; D019881:Aminoacyltransferases / Q000235:genetics; D017103:Bacillus Phages / Q000378:metabolism* / Q000648:ultrastructure; D001408:Bacillus anthracis / Q000235:genetics* / Q000378:metabolism / Q000821:virology*; D001426:Bacterial Proteins / Q000235:genetics; D001483:Base Sequence; D002473:Cell Wall / Q000378:metabolism / Q000821:virology; D003546:Cysteine Endopeptidases; D008854:Microscopy, Electron; D008969:Molecular Sequence Data; D011991:Receptors, Virus / Q000235:genetics* / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D011991:Receptors, Virus; D019881:Aminoacyltransferases; C120542:sortase A; D003546:Cysteine Endopeptidases