Comparison of the conjugal transfer (tra) regions in selected plasmids. pMP118, the megaplasmid from L. salivarius UCC118 (5); pMRC01, the conjugative plasmid from L. lactis DPC3147 (11); pWCFS103, the conjugative plasmid from L. plantarum NCIMB8826 (55); pSF118-20 and pSF118-44, plasmids from L. salivarius UCC118 (5). Percentages of identity in the translated nucleotide sequences of each gene are indicated. The identities of trsB, trsC, trsD, trsJ, and trsL from pMRCO1 and pWCFS103 are 72%, 73%, 80%, 48%, and 44%, respectively.