FIG. 1.

Genetic organization of the hprK region of S. xylosus. The sequenced region around the HPr kinase gene is shown. The thick line represents the DNA that was obtained from a genomic S. xylosus library. DNA indicated by the thin line was obtained by PCR. Sizes and orientations of the genes were deduced from the nucleotide sequence. The site of insertion and the orientation of the erythromycin resistance gene ermB in the HPr kinase mutants S. xylosus TX66 and TX67 are indicated. The nucleotide sequence of the hprK promoter region is shown below the genetic organization. Numbering refers to the complete DNA sequence (accession no. AJ243915). The transcriptional start site is marked by an arrow.