Identification of the replication region of the Lactobacillus acidophilus plasmid pLA106

The complete nucleotide sequence of plasmid pLA106 (2862 bp) from Lactobacillus acidophilus TK8912 was determined. Based on this sequence, the location of the genes for mobilization-plasmid recombination protein (mob), replication origin (ori), transcriptional repressor protein (repA) and replication initiation protein (repB) were predicted. Deletion analysis showed that the 1.4-kb PstI-EcoRV fragment carrying the ori, repA and repB genes is able to replicate in Lactobacillus and Escherichia coli cells. The plasmid pLA106 appears to have most features of the pLS1/pE194 plasmid family.