title: Halocin C8: an antimicrobial peptide distributed among four halophilic archaeal genera: Natrinema, Haloterrigena, Haloferax, and Halobacterium.
abstract: Halophilic archaea thrive in hypersaline ecosystems and produce antimicrobial peptides (AMPs) named halocins. AMPs are essential effectors of microbial interactions in natural ecosystems. Halocin C8 is a 7.4 kDa peptide produced by Natrinema sp. AS7092. Surrounded by genes involved in regulation and transport, the halC8 gene encodes a precursor, processed into the mature halocin and an immunity protein, protecting the producing strain against its halocin. This feature constitutes a unique property of halocin C8, as known AMPs and their immunity proteins are generally encoded on distinct ORFs in an operon. By complementary in silico and PCR-based approaches, the presence of halC8 in halophilic archaea collected from various parts of the world was evidenced. The full-length halC8 gene is restricted and consistently found in the genomes of strains belonging to the phylogenetically related genera Natrinema and Haloterrigena, along with transport and regulation genes. Functional expression of halC8 was demonstrated by RT-PCR and antimicrobial assays. Active halocin C8 was shown to contain five disulphide bridges, presumably conferring a compact structure resistant to harsh environmental conditions. In other archaeal genera, Haloferax and Halobacterium, genes encoding halocin C8 with diverging immunity protein moiety were evidenced. A phylogenetic analysis of halocin C8 sequences was conducted.
authors.affiliation: Molécules de Communication et Adaptation des Microorganismes (MCAM, UMR 7245 CNRS-MNHN), Sorbonne Universités, Muséum National d'Histoire Naturelle, Centre national de la Recherche scientifique (CNRS), CP 54, 57 rue Cuvier, 75005, Paris, France.
authors.forename: Alison
authors.initials: A
authors.lastname: Besse
authors.affiliation: Molécules de Communication et Adaptation des Microorganismes (MCAM, UMR 7245 CNRS-MNHN), Sorbonne Universités, Muséum National d'Histoire Naturelle, Centre national de la Recherche scientifique (CNRS), CP 54, 57 rue Cuvier, 75005, Paris, France.
authors.forename: Manon
authors.initials: M
authors.lastname: Vandervennet
authors.affiliation: Molécules de Communication et Adaptation des Microorganismes (MCAM, UMR 7245 CNRS-MNHN), Sorbonne Universités, Muséum National d'Histoire Naturelle, Centre national de la Recherche scientifique (CNRS), CP 54, 57 rue Cuvier, 75005, Paris, France.
authors.forename: Christophe
authors.initials: C
authors.lastname: Goulard
authors.affiliation: Molécules de Communication et Adaptation des Microorganismes (MCAM, UMR 7245 CNRS-MNHN), Sorbonne Universités, Muséum National d'Histoire Naturelle, Centre national de la Recherche scientifique (CNRS), CP 54, 57 rue Cuvier, 75005, Paris, France.
authors.forename: Jean
authors.initials: J
authors.lastname: Peduzzi
authors.affiliation: Molécules de Communication et Adaptation des Microorganismes (MCAM, UMR 7245 CNRS-MNHN), Sorbonne Universités, Muséum National d'Histoire Naturelle, Centre national de la Recherche scientifique (CNRS), CP 54, 57 rue Cuvier, 75005, Paris, France.
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Isaac
authors.affiliation: Molécules de Communication et Adaptation des Microorganismes (MCAM, UMR 7245 CNRS-MNHN), Sorbonne Universités, Muséum National d'Histoire Naturelle, Centre national de la Recherche scientifique (CNRS), CP 54, 57 rue Cuvier, 75005, Paris, France.
authors.forename: Sylvie
authors.initials: S
authors.lastname: Rebuffat
authors.affiliation: Molécules de Communication et Adaptation des Microorganismes (MCAM, UMR 7245 CNRS-MNHN), Sorbonne Universités, Muséum National d'Histoire Naturelle, Centre national de la Recherche scientifique (CNRS), CP 54, 57 rue Cuvier, 75005, Paris, France. acarre@mnhn.fr.
authors.forename: Alyssa
authors.initials: A
authors.lastname: Carré-Mlouka
mesh_terms: D019843:Archaeal Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D001430:Bacteriocins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D004220:Disulfides / Q000737:chemistry; D000071251:Extreme Environments; D019766:Genes, Archaeal; D006216:Halobacteriaceae / Q000145:classification / Q000235:genetics* / Q000378:metabolism; D016366:Open Reading Frames; D009876:Operon; D010802:Phylogeny; D054712:Salinity
chemical_list: D019843:Archaeal Proteins; D001430:Bacteriocins; D004220:Disulfides
keywords: Antimicrobial peptides; Halocin C8; Halophilic archaea; Haloterrigena; Hypersaline ecosystems; Natrinema