Molecular Analysis of p141 Isolated from Lactobacillus plantarum KLDS1.0728

Abstract:

A plasmid from Lactobacillus plantarum KLDS1.0728, designated as p141, was sequenced and characterized. It consisted of a 3597 bp circular molecule with a G + C content of 38%. The enzyme digestion map of plasmid p141 was obtained by the software DNAMAN 6.0. The plasmid p141 was predicted to contain 15 ORFs by ORF Finder software in NCBI. Using the blast software to compare and search the genes, we found two known ORFs in the plasmid p141. Among those, rep gene was most important for plasmid replication ability. Identity analysis indicated that rep gene of p141 was similar to that of Lactobacillus plantarum WCFS1 plasmid pWCFS101 and Lactobacillus plantarum plasmid pM4. Based on the sequence similarities among minimal replicon modules, p141 belonged to Group III family in the RCR plasmid. In addition, mob gene was existed in p141, so this plasmid had level transfer ability. But Tn4430 transposon and transposase gene topl, topA were not found in p141, and this indicated that genes of the plasmid p141 were stable. There were direct and invert repeats in this plasmid. These repeats had certain association with plasmid replication and transfer regulation, protein expression, also had significance on the regulation of plasmid copy number.

Key words:Lactobacillus plantarum, Plasmid, Sequence analysis