Plasmid pP62BP1 isolated from an Arctic Psychrobacter sp. strain carries two highly homologous type II restriction-modification systems and a putative organic sulfate metabolism operon

Abstract

The complete nucleotide sequence of plasmid pP62BP1 (34,467 bp), isolated from Arctic Psychrobacter sp. DAB_AL62B, was determined and annotated. The conserved plasmid backbone is composed of several genetic modules, including a replication system (REP) with similarities to the REP region of the iteron-containing plasmid pPS10 of Pseudomonas syringae. The additional genetic load of pP62BP1 includes two highly related type II restriction-modification systems and a set of genes (slfRCHSL) encoding enzymes engaged in the metabolism of organic sulfates, plus a putative transcriptional regulator (SlfR) of the AraC family. The pP62BP1 slflocus has a compact and unique structure. It is predicted that the enzymes SlfC, SlfH, SlfS and SlfL carry out a chain of reactions leading to the transformation of alkyl sulfates into acyl-CoA, with dodecyl sulfate (SDS) as a possible starting substrate. Comparative analysis of the nucleotide sequences of pP62BP1 and other Psychrobacter spp. plasmids revealed their structural diversity. However, the presence of a few highly conserved DNA segments in pP62BP1, plasmid 1 of P. cryohalolentis K5 and pRWF-101 of Psychrobacter sp. PRwf-1 is indicative of recombinational shuffling of genetic information, and is evidence of lateral gene transfer in the Arctic environment.

Plasmid diversity in arctic strains of Psychrobacter spp.

“…One of the randomly chosen strains ( Psychrobacter sp. DAB_AL62B) was already described in our previous study (Lasek et al 2012). The remaining strains were subjected to further analysis.…”

“…MRS act to resolve plasmid oligomers and this activity increases the number of independent plasmid molecules available for distribution during cell division (Bahl et al 2009). Homologs of ORF10 have been identified in other Psychrobacter plasmids, including pRWF101 of PRwf-1 and pP62BP1 of DAB_AL62B (Lasek et al 2012). …”

“…R-M systems are frequently carried by plasmids, e.g. pP62BP2 of Psychrobacter DAB_AL62B contains two nearly identical modules of this type (Lasek et al 2012). It has been demonstrated that R-M systems act in an analogous manner to TA modules, which stabilize plasmids by eliminating plasmid-less cells from the bacterial population (Kobayashi 2001).…”

“…PRwf-1. Only pP62BP1 (characterized in our previous study) contains a defined genetic module of adaptive value that has been linked with a specific phenotype, namely transformation of alkyl sulfates into acyl-CoA, with dodecyl sulfate (SDS) as a possible substrate (organic sulfates metabolism) (Lasek et al 2012). The other three plasmids seem to be cryptic replicons encoding proteins involved in replication, stabilization and conjugal transfer, as well as hypothetical proteins, mostly of unknown function.…”

Genetic structure and biological properties of the first ancient multiresistance plasmid pKLH80 isolated from a permafrost bacterium

“…have added significant amounts of data on plasmid diversity; however, only one plasmid (Psychrobacter cryohalolentis K5 plasmid 1) has been isolated from ancient permafrost bacteria of this genus and this plasmid carried no antibiotic resistance genes (Lasek et al, 2012;Dziewit et al, 2013).…”