The Large pBS32/pLS32 Plasmid of Ancestral Bacillus subtilis

J Bacteriol. 2020 Aug 25;202(18):e00290-20. doi: 10.1128/JB.00290-20. Print 2020 Aug 25.


The ancestral strain of Bacillus subtilis NCIB3610 (3610) bears a large, low-copy-number plasmid, called pBS32, that was lost during the domestication of laboratory strain derivatives. Selection against pBS32 may have been because it encodes a potent inhibitor of natural genetic competence (ComI), as laboratory strains were selected for high-frequency transformation. Previous studies have shown that pBS32 and its sibling, pLS32 in Bacillus subtilis subsp. natto, encode a replication initiation protein (RepN), a plasmid partitioning system (AlfAB), a biofilm inhibitor (RapP), and an alternative sigma factor (SigN) that can induce plasmid-mediated cell death in response to DNA damage. Here, we review the literature on pBS32/pLS32, the genes found on it, and their associated phenotypes.

Keywords: AlfAB; DNA segregation; Rap phosphatases; RapP; SigN; biofilms; domestication; megaplasmids; plasmid replication; sigma factors.

Publication types

  • Research Support, N.I.H., Extramural
  • Review

MeSH terms

  • Bacillus subtilis / genetics*
  • Bacterial Proteins / genetics*
  • Biofilms
  • Gene Expression Regulation, Bacterial
  • Plasmids*


  • Bacterial Proteins