FIG. 1.

Identification and expression of the genetic determinants of AbiT encoded on pED1. (A) Restriction map and pertinent subclones of pED1 with their respective Abi phenotype. The smallest Abi⁺ region obtained is delimited by a gray box. (B) DNA sequence analysis of the 2,711-bp HaeII fragment and inactivation of the ORFs. The putative promoter is indicated by a thin arrow, and predicted genes are indicated by large arrows. Regions of homology with lactococcal plasmids are shown in gray; the hatched box is a region of homology with E. faecalis and S. pneumoniae transposons. X, frameshift. (C) Hybridization of RNA isolated from AbiT-containing L. lactis strains with a labeled DNA fragment of abiTi, abiTii, and orf98-orf109. Lane 1, MG1363(pED100); lane 2, MG1363(pED107). The size of the transcripts was evaluated with a 0.24- to 9.5-kb RNA ladder (Invitrogen).