title: Surface protein IsdC and Sortase B are required for heme-iron scavenging of Bacillus anthracis.
abstract: Bacillus anthracis, the spore-forming agent of anthrax, requires iron for growth and is capable of scavenging heme-iron during infection. We show here that the B. anthracis iron-regulated surface determinants (isd) locus encompasses isdC, specifying a heme-iron binding surface protein. Anchoring of IsdC to the cell wall envelopes of vegetative bacilli requires srtB, which encodes sortase B. Purified sortase B cleaves IsdC between the threonine and the glycine of its NPKTG motif sorting signal. B. anthracis variants lacking either isdC or srtB display defects in heme-iron scavenging, suggesting that IsdC binding to heme-iron in the cell wall envelope contributes to bacterial uptake of heme.
authors.affiliation: Department of Microbiology, University of Chicago, Chicago, IL 60637, USA.
authors.forename: Anthony W
authors.initials: AW
authors.lastname: Maresso
authors.forename: Travis J
authors.initials: TJ
authors.lastname: Chapa
authors.forename: Olaf
authors.initials: O
authors.lastname: Schneewind
mesh_terms: D000595:Amino Acid Sequence; D019881:Aminoacyltransferases / Q000502:physiology*; D001408:Bacillus anthracis / Q000235:genetics / Q000378:metabolism*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D003546:Cysteine Endopeptidases / Q000502:physiology*; D006418:Heme / Q000378:metabolism*; D007501:Iron / Q000378:metabolism*; D008969:Molecular Sequence Data; D010457:Peptidoglycan / Q000378:metabolism; D011485:Protein Binding; D016415:Sequence Alignment
chemical_list: D001426:Bacterial Proteins; D002352:Carrier Proteins; D010457:Peptidoglycan; C509821:sortase B; D006418:Heme; D007501:Iron; D019881:Aminoacyltransferases; D003546:Cysteine Endopeptidases