Two Inducible Prophages of an Antarctic Pseudomonas sp. ANT_H14 Use the Same Capsid for Packaging Their Genomes - Characterization of a Novel Phage Helper-Satellite System

PLoS One. 2016 Jul 7;11(7):e0158889. doi: 10.1371/journal.pone.0158889. eCollection 2016.

Abstract

Two novel prophages ФAH14a and ФAH14b of a psychrotolerant Antarctic bacterium Pseudomonas sp. ANT_H14 have been characterized. They were simultaneously induced with mitomycin C and packed into capsids of the same size and protein composition. The genome sequences of ФAH14a and ФAH14b have been determined. ФAH14b, the phage with a smaller genome (16,812 bp) seems to parasitize ФAH14a (55,060 bp) and utilizes its capsids, as only the latter encodes a complete set of structural proteins. Both viruses probably constitute a phage helper-satellite system, analogous to the P2-P4 duo. This study describes the architecture and function of the ФAH14a and ФAH14b genomes. Moreover, a functional analysis of a ФAH14a-encoded lytic enzyme and a DNA methyltransferase was performed. In silico analysis revealed the presence of the homologs of ФAH14a and ФAH14b in other Pseudomonas genomes, which may suggest that helper-satellite systems related to the one described in this work are common in pseudomonads.

MeSH terms

  • Antarctic Regions
  • Bacteriophages / genetics*
  • Capsid / metabolism
  • Capsid Proteins / genetics
  • DNA (Cytosine-5-)-Methyltransferases / genetics
  • DNA Mutational Analysis
  • DNA, Viral / metabolism
  • Gene Expression Regulation, Viral
  • Genes, Viral
  • Helper Viruses / genetics
  • Prophages / genetics*
  • Pseudomonas / virology*
  • Satellite Viruses / genetics*
  • Soil Microbiology
  • Virus Activation

Substances

  • Capsid Proteins
  • DNA, Viral
  • DNA (Cytosine-5-)-Methyltransferases

Grants and funding

This work was supported by the National Science Centre, Poland (grant number DEC-2013/09/D/NZ8/03046). The funder had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.