FIG. 1.

Physical and genetic maps of virulence plasmid sequences and recombinant plasmids used in this study. The top line depicts the insert of pGTR061, which carries spvRABCD, whose open reading frames are indicated by arrows with the direction of transcription shown. Restriction sites indicated below pGTR061 are as follows: B, BamHI; C, ClaI; E, EcoRI; M, MscI; P, PstI; and S, StuI. Note that pGTR061 extends to the XhoI site on the right. The rightmost BamHI site is indicated for reference to plasmids depicted below. The extent of the ΔspvB30 deletion and the location of the spvC22::Tn5 insertion are shown. The ClaI insert of pGTR040 corresponds to the Δspv::tet deletion of UF110. The arrows next to the insertion sequences of each clone indicate the direction of transcription of the promoters of the respective vectors. For pGTR333, pGTR337, and pGTR338, the broken line indicates that the EcoRI-PstI fragment carrying the spvA promoter has been juxtaposed to the spvB open reading frame by the PstI deletion. Details of plasmid construction are presented in Table 1.