title: Isolation and characterization of two members of the siderophore-microcin family, microcins M and H47.
abstract: In this paper we provide the first biochemical evidence of the existence of a family of structure-related antimicrobial peptides, the siderophore-microcins, in the Enterobacteriaceae family. We isolated and characterized two novel siderophore-microcins, MccM and MccH47, previously characterized through genetic studies. MccM and MccH47 were expressed from several Escherichia coli strains containing the microcin gene clusters. The spectra of their bactericidal activities were found to be restricted to some species of the Enterobacteriaceae. MccM and MccH47 were unable to inhibit the growth of strains carrying mutations in the fepA, cir, and fiu genes, which showed the requirement of the iron-catecholate receptors for their recognition. The MccM and MccH47 peptide moieties contain 77 and 60 residues, respectively, and are derived from the microcin precursors McmA and MchB, respectively. In addition, both peptides carried a C-terminal posttranslational modification containing a salmochelin-like siderophore moiety also found in MccE492 (X. Thomas et al., J. Biol. Chem., 279:28233-28242, 2004). Interestingly, when MccM was isolated from E. coli Nissle 1917, which lacks the two genes necessary for modification biosynthesis, it was devoid of posttranslational modification. Those two genes could be complemented by their homologues from the MccH47 gene cluster, thereby showing their functional interchangeability between at least two members of the siderophore-microcin family. Finally, from the sequence analysis of the MccE492 gene cluster, we hypothesized the existence of an additional member of the siderophore-microcin family. Therefore, we propose that the siderophore-microcin family contains five representatives.
authors.affiliation: Molécules de Communication et Adaptation des Micro-organismes, CNRS, Muséum National d'Histoire Naturelle, FRE 3206, CP 54, 57 rue Cuvier, Paris 75005, France.
authors.forename: Gaëlle
authors.initials: G
authors.lastname: Vassiliadis
authors.forename: Delphine
authors.initials: D
authors.lastname: Destoumieux-Garzón
authors.forename: Carine
authors.initials: C
authors.lastname: Lombard
authors.forename: Sylvie
authors.initials: S
authors.lastname: Rebuffat
authors.forename: Jean
authors.initials: J
authors.lastname: Peduzzi
mesh_terms: D000595:Amino Acid Sequence; D000900:Anti-Bacterial Agents / Q000737:chemistry*; D023181:Antimicrobial Cationic Peptides; D001425:Bacterial Outer Membrane Proteins / Q000187:drug effects; D003087:Colicins / Q000737:chemistry* / Q000235:genetics*; D004591:Electrophoresis, Polyacrylamide Gel; D004755:Enterobacteriaceae / Q000737:chemistry* / Q000235:genetics*; D004926:Escherichia coli / Q000235:genetics; D006868:Hydrolysis; D007711:Klebsiella pneumoniae / Q000187:drug effects / Q000235:genetics; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry* / Q000235:genetics; D010802:Phylogeny; D010957:Plasmids / Q000235:genetics; D011499:Protein Processing, Post-Translational / Q000235:genetics; D011956:Receptors, Cell Surface / Q000187:drug effects; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D014357:Trypsin / Q000737:chemistry
chemical_list: D000900:Anti-Bacterial Agents; D023181:Antimicrobial Cationic Peptides; D001425:Bacterial Outer Membrane Proteins; D003087:Colicins; D010455:Peptides; D011956:Receptors, Cell Surface; C444452:microcin H47; C035902:siderophore receptors; D014357:Trypsin