A histidine kinase and a response regulator provide phage resistance to Marinomonas mediterranea via CRISPR-Cas regulation

Sci Rep. 2021 Oct 18;11(1):20564. doi: 10.1038/s41598-021-99740-9.

Abstract

CRISPR-Cas systems are used by many prokaryotes to defend against invading genetic elements. In many cases, more than one CRISPR-Cas system co-exist in the same cell. Marinomonas mediterranea MMB-1 possesses two CRISPR-Cas systems, of type I-F and III-B respectively, which collaborate in phage resistance raising questions on how their expression is regulated. This study shows that the expression of both systems is controlled by the histidine kinase PpoS and a response regulator, PpoR, identified and cloned in this study. These proteins show similarity to the global regulators BarA/UvrY. In addition, homologues to the sRNAs CsrB and CsrC and the gene coding for the post-transcriptional repressor CsrA have been also identified indicating the conservation of the elements of the BarA/UvrY regulatory cascade in M. mediterranea. RNA-Seq analyses have revealed that all these genetics elements are regulated by PpoS/R supporting their participation in the regulatory cascade. The regulation by PpoS and PpoR of the CRISPR-Cas systems plays a role in phage defense since mutants in these proteins show an increase in phage sensitivity.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacterial Proteins / metabolism
  • Bacteriophages / genetics*
  • CRISPR-Cas Systems
  • Gene Expression
  • Histidine Kinase / genetics
  • Histidine Kinase / metabolism*
  • Marinomonas / genetics
  • Marinomonas / metabolism*
  • RNA-Binding Proteins / metabolism
  • Repressor Proteins / genetics
  • Transcription Factors / metabolism

Substances

  • Bacterial Proteins
  • RNA-Binding Proteins
  • Repressor Proteins
  • Transcription Factors
  • Histidine Kinase

Supplementary concepts

  • Marinomonas mediterranea