title: Bacillus anthracis sortase A (SrtA) anchors LPXTG motif-containing surface proteins to the cell wall envelope.
abstract: Cell wall-anchored surface proteins of gram-positive pathogens play important roles during the establishment of many infectious diseases, but the contributions of surface proteins to the pathogenesis of anthrax have not yet been revealed. Cell wall anchoring in Staphylococcus aureus occurs by a transpeptidation mechanism requiring surface proteins with C-terminal sorting signals as well as sortase enzymes. The genome sequence of Bacillus anthracis encodes three sortase genes and eleven surface proteins with different types of cell wall sorting signals. Purified B. anthracis sortase A cleaved peptides encompassing LPXTG motif-type sorting signals between the threonine (T) and the glycine (G) residues in vitro. Sortase A activity could be inhibited by thiol-reactive reagents, similar to staphylococcal sortases. B. anthracis parent strain Sterne 34F(2), but not variants lacking the srtA gene, anchored the collagen-binding MSCRAMM (microbial surface components recognizing adhesive matrix molecules) BasC (BA5258/BAS4884) to the bacterial cell wall. These results suggest that B. anthracis SrtA anchors surface proteins bearing LPXTG motif sorting signals to the cell wall envelope of vegetative bacilli.
authors.affiliation: Department of Microbiology, University of Chicago, 920 East 58th Street, Chicago, IL 60637, USA.
authors.forename: Andrew H
authors.initials: AH
authors.lastname: Gaspar
authors.forename: Luciano A
authors.initials: LA
authors.lastname: Marraffini
authors.forename: Elizabeth M
authors.initials: EM
authors.lastname: Glass
authors.forename: Kristin L
authors.initials: KL
authors.lastname: Debord
authors.forename: Hung
authors.initials: H
authors.lastname: Ton-That
authors.forename: Olaf
authors.initials: O
authors.lastname: Schneewind
mesh_terms: D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D019881:Aminoacyltransferases / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D000818:Animals; D000881:Anthrax / Q000382:microbiology; D001408:Bacillus anthracis / Q000472:pathogenicity / Q000502:physiology*; D001426:Bacterial Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D003546:Cysteine Endopeptidases; D005998:Glycine; D008565:Membrane Proteins / Q000737:chemistry / Q000378:metabolism; D051379:Mice; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000302:isolation & purification / Q000378:metabolism; D016415:Sequence Alignment; D013912:Threonine; D014774:Virulence
chemical_list: D001426:Bacterial Proteins; D008565:Membrane Proteins; D010446:Peptide Fragments; D013912:Threonine; D019881:Aminoacyltransferases; C120542:sortase A; D003546:Cysteine Endopeptidases; D005998:Glycine