Sequence analysis of plasmid pIR52-1 from Lactobacillus helveticus R0052 and investigation of its origin of replication

Plasmid. 2010 Mar;63(2):108-17. doi: 10.1016/j.plasmid.2009.12.004. Epub 2010 Jan 4.


Lactobacillus helveticus R0052 is a bacterium used in commercial probiotic preparations. R0052 contains a small, cryptic plasmid comprised of eight open reading frames, four of which encode proteins of unknown function. Based on the sequence of the replication initiation protein RepA, pIR52-1 is a member of the recently described RepA_N family of Gram-positive theta-replicating plasmids. The repA gene of pIR52-1 is the minimal origin of replication for L. helveticus and other Lactobacillus hosts. Additionally, pIR52-1 belongs to a subgroup of the RepA_N plasmid family which have RepA proteins of high amino acid identity and a conserved, non-coding element upstream of repA which, in pIR52-1, is responsible for the control of plasmid copy number and contributes to plasmid maintenance.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacterial Proteins / genetics
  • Bacterial Proteins / metabolism
  • Base Sequence
  • DNA Replication / genetics
  • Gene Dosage
  • Genetic Vectors / genetics
  • Lactobacillus helveticus / genetics*
  • Lactobacillus plantarum / genetics
  • Molecular Sequence Data
  • Plasmids / genetics*
  • Replication Origin / genetics*
  • Sequence Analysis, DNA*
  • Transformation, Genetic


  • Bacterial Proteins