FIG. 3.

Genomic region of S. meliloti 1021 complementing the PE-deficient mutant KDR310. Schematic representation of the genomic DNA insert of cosmid pCOS9.4 complementing PE deficiency. The subcloning strategy is shown with the 6.6-kb DNA region (pTB2009) and the 2.1-kb HindIII-BamHI fragment that was sequenced (pTB2036). The location and direction of one partial ORF, encoding an ABC transporter-like protein (smABC), and two complete ORFs, encoding Psd (psd) and Pss (pssA), are shown by arrows. The replacement of the pssA gene by a gentamicin resistance cassette (Gm^R) in mutant CS111 is indicated. Restriction sites (B, BamHI; L, BclI; E, EcoRI; H, HindIII; N, NcoI; S, SmaI; X, XhoI) used are shown.