Isolation of strong promoters from Clavibacter xyli subsp. cynodontis using a promoter probe plasmid.

To isolate promoters from Clavibacter xyli subsp. cynodontis (C. xyli subsp. cynodontis), we constructed a new promoter probe plasmid and made a C. xyli subsp. cynodontis promoter probe library. Two promoters gave over 2500-times stronger expression than the parental plasmid. The promoters were sequenced and compared to other bacterial promoters. These C. xyli subsp. cynodontis promoter regions are GC-rich and do not resemble E. coli promoters, but do resemble a few individual promoters found in streptomycetes.