title: Analysis of defence systems and a conjugative IncP-1 plasmid in the marine polyaromatic hydrocarbons-degrading bacterium Cycloclasticus sp. 78-ME.
abstract: Marine prokaryotes have evolved a broad repertoire of defence systems to protect their genomes from lateral gene transfer including innate or acquired immune systems and infection-induced programmed cell suicide and dormancy. Here we report on the analysis of multiple defence systems present in the genome of the strain Cycloclasticus sp. 78-ME isolated from petroleum deposits of the tanker 'Amoco Milford Haven'. Cycloclasticus are ubiquitous bacteria globally important in polyaromatic hydrocarbons degradation in marine environments. Two 'defence islands' were identified in 78-ME genome: the first harbouring CRISPR-Cas with toxin-antitoxin system, while the second was composed by an array of genes for toxin-antitoxin and restriction-modification proteins. Among all identified spacers of CRISPR-Cas system only seven spacers match sequences of phages and plasmids. Furthermore, a conjugative plasmid p7ME01, which belongs to a new IncP-1θ ancestral archetype without any accessory mobile elements was found in 78-ME. Our results provide the context to the co-occurrence of diverse defence mechanisms in the genome of Cycloclasticus sp. 78-ME, which protect the genome of this highly specialized PAH-degrader. This study contributes to the further understanding of complex networks established in petroleum-based microbial communities.
authors.affiliation: Institute for Coastal Marine Environment, CNR, Spianata S. Raineri 86, Messina, 98122, Italy.
authors.forename: Michail M
authors.initials: MM
authors.lastname: Yakimov
authors.affiliation: Institute for Coastal Marine Environment, CNR, Spianata S. Raineri 86, Messina, 98122, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Crisafi
authors.affiliation: Institute for Coastal Marine Environment, CNR, Spianata S. Raineri 86, Messina, 98122, Italy.
authors.forename: Enzo
authors.initials: E
authors.lastname: Messina
authors.affiliation: Institute for Coastal Marine Environment, CNR, Spianata S. Raineri 86, Messina, 98122, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Smedile
authors.affiliation: Institute of Molecular Genetics and Gene Biology, Russian Academy of Sciences, Moscow, Russia.
authors.forename: Anna
authors.initials: A
authors.lastname: Lopatina
authors.affiliation: Institute for Coastal Marine Environment, CNR, Spianata S. Raineri 86, Messina, 98122, Italy.
authors.forename: Renata
authors.initials: R
authors.lastname: Denaro
authors.affiliation: Microbial Interactions and Processes Research Group, HZI - Helmholtz Centre for Infection Research, Inhoffenstraße 7, Braunschweig, D-38124, Germany.
authors.forename: Dietmar H
authors.initials: DH
authors.lastname: Pieper
authors.affiliation: School of Biological Sciences, Bangor University, ECW Bldg Deiniol Rd, Bangor, Gwynedd, LL57 2UW, United Kingdom.
authors.forename: Peter N
authors.initials: PN
authors.lastname: Golyshin
authors.affiliation: Institute for Coastal Marine Environment, CNR, Spianata S. Raineri 86, Messina, 98122, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Giuliano
mesh_terms: D001711:Biotransformation; D064113:CRISPR-Cas Systems; D015280:DNA Restriction-Modification Enzymes; D005798:Genes, Bacterial; D044404:Genomic Islands; D006838:Hydrocarbons / Q000378:metabolism*; D044147:Piscirickettsiaceae / Q000235:genetics* / Q000378:metabolism*; D010957:Plasmids / Q000032:analysis* / Q000145:classification*; D012623:Seawater / Q000382:microbiology
chemical_list: D015280:DNA Restriction-Modification Enzymes; D006838:Hydrocarbons