A Novel Regulator PepR Regulates the Expression of Dipeptidase Gene in .

produces insecticidal crystal proteins encoded by or genes and targets a variety of insect pests. We previously found that a strong promoter of a DeoR family transcriptional regulator (HD73_5014) can efficiently drive expression in HD73. Here, we investigated the regulation of neighbor genes by HD73_5014. The HD73_5014 homologs are widely distributed in Gram-positive bacterial species. Its neighbor genes include , , and , which encode dipeptidase, rRNA pseudouridine synthase and polysaccharide biosynthesis protein, respectively. The four open reading frames (ORFs) are organized to be a gene cluster in HD73. RT-PCR analysis revealed that the and genes formed a transcriptional unit (- operon), while formed a transcriptional unit in HD73. Promoter- fusion assays showed that the and - promoters are regulated by HD73_5014. EMSA experiments showed that HD73_5014 directly binds to the promoter region but not to the - promoter region. Thus, the HD73_5014 transcriptional regulator, which controls the expression of the dipeptidase , was named PepR (dipeptidase regulator). We also confirmed the direct regulation between PepR and PepV by the increased sensitivity to vancomycin in Δ and Δ mutants compared to HD73.