FIG. 1.

Genetic map of pGNB1 accessory regions L1 and L2. Coding regions are indicated by arrows showing the direction of transcription. kluB (putative postsegregational killing gene), trfA (replication initiation gene), trbN and trbO (mating pair formation genes), and traC (conjugative transfer gene) are indicated by open arrows and represent plasmid backbone genes. Accessory region L1 contains a transposon related to Tn5501, a new insertion sequence element (ISGNB1-1), and a gene, orf2, encoding a conserved protein (Cupin 2 conserved barrel protein) having an unknown function. Recombinant plasmid pIK401 contains a PstI (P) restriction fragment with orf2. The origin of vegetative replication (oriV) is indicated by a filled circle. Accessory region L2 contains the triphenylmethane reductase gene (tmr) and a truncated dihydrolipoamide dehydrogenase gene (′lpdA) which is flanked by IS1071 and ISGNB1-2. Subcloning of a 2.4-kb NotI (N) restriction fragment, a 5.8-kb SphI (S) restriction fragment, and a 5.4-BamHI (B) restriction fragment resulted in recombinant plasmids pIK402, pIK403, and pIK404, respectively. These plasmids were tested to determine whether they conferred resistance to antimicrobial drugs and triphenylmethane dyes.