FIG. 2.

Deletion and complementation analysis of the bvgR locus. The transcriptional activities of the vrg6-phoA transcriptional fusions in wild-type (WT) strain TM1081, strain TM1126, and strain TM1126 bearing the indicated pTM193 derivatives are shown. The bvg sequences inserted into the multiple cloning site of each pTM193 derivative are indicated by solid lines. (A) Effects of pTM193 alone and pTM193 bearing large restriction fragments derived from the bvg locus on expression of the vrg6 locus. (B) Effects of pTM193 bearing truncated versions of the bvg BglII-XhoI restriction fragment on expression of the vrg6 locus. The endpoints of deletions are indicated in parentheses. Nucleotide numbers correspond to those in the published sequence of bvgAS (3). Alkaline phosphatase activities are reported relative to strain TM1081 grown in the presence of MgSO₄ (36.1 units). All reported values are averages of at least six independent assays. Restriction enzyme recognition sequences are indicated as follows: E, EcoRI; B, BamHI; S, SalI; X, XhoI; Bg, BglII.