title: The solute-binding component of a putative Mn(II) ABC transporter (MntA) is a novel Bacillus anthracis virulence determinant.
abstract: Here we describe the characterization of a lipoprotein previously proposed as a potential Bacillus anthracis virulence determinant and vaccine candidate. This protein, designated MntA, is the solute-binding component of a manganese ion ATP-binding cassette transporter. Coupled proteomic-serological screen of a fully virulent wild-type B. anthracis Vollum strain, confirmed that MntA is expressed both in vitro and during infection. Expression of MntA is shown to be independent of the virulence plasmids pXO1 and pXO2. An mntA deletion, generated by allelic replacement, results in complete loss of MntA expression and its phenotypic analysis revealed: (i) impaired growth in rich media, alleviated by manganese supplementation; (ii) increased sensitivity to oxidative stress; and (iii) delayed release from cultured macrophages. The DeltamntA mutant expresses the anthrax-associated classical virulence factors, lethal toxin and capsule, in vitro as well as in vivo, and yet the mutation resulted in severe attenuation; a 10(4)-fold drop in LD(50) in a guinea pig model. MntA expressed in trans allowed to restore, almost completely, the virulence of the DeltamntA B. anthracis strain. We propose that MntA is a novel B. anthracis virulence determinant essential for the development of anthrax disease, and that B. anthracisDeltamntA strains have the potential to serve as platform for future live attenuated vaccines.
authors.affiliation: Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, PO Box 19, Ness Ziona, 74100, Israel.
authors.forename: Orit
authors.initials: O
authors.lastname: Gat
authors.forename: Itai
authors.initials: I
authors.lastname: Mendelson
authors.forename: Theodor
authors.initials: T
authors.lastname: Chitlaru
authors.forename: Naomi
authors.initials: N
authors.lastname: Ariel
authors.forename: Zeev
authors.initials: Z
authors.lastname: Altboum
authors.forename: Haim
authors.initials: H
authors.lastname: Levy
authors.forename: Shay
authors.initials: S
authors.lastname: Weiss
authors.forename: Haim
authors.initials: H
authors.lastname: Grosfeld
authors.forename: Sara
authors.initials: S
authors.lastname: Cohen
authors.forename: Avigdor
authors.initials: A
authors.lastname: Shafferman
mesh_terms: D018528:ATP-Binding Cassette Transporters / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D001408:Bacillus anthracis / Q000235:genetics / Q000378:metabolism* / Q000472:pathogenicity*; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D002478:Cells, Cultured; D005260:Female; D006168:Guinea Pigs; D006801:Humans; D007501:Iron / Q000378:metabolism; D008074:Lipoproteins / Q000235:genetics / Q000378:metabolism; D008264:Macrophages / Q000166:cytology / Q000378:metabolism; D008345:Manganese / Q000378:metabolism; D008969:Molecular Sequence Data; D010957:Plasmids / Q000235:genetics / Q000378:metabolism; D020543:Proteome / Q000032:analysis; D016415:Sequence Alignment
chemical_list: D018528:ATP-Binding Cassette Transporters; D001426:Bacterial Proteins; D008074:Lipoproteins; D020543:Proteome; D008345:Manganese; D007501:Iron