Promoter cloning in the radioresistant bacterium Deinococcus radiodurans

Deinococcus radiodurans is a highly radiation-resistant bacterium that is c lassed in a major subbranch of the bacterial domain. Since very little is k nown about gene expression in this bacterium, an initial study of promoters was undertaken. In order to isolate promoters and study promoter function, a series of integrative vectors for stable chromosomal insertion in D. rad iodurans were developed. These vectors are based on Escherichia coli replic ons that are unable to replicate autonomously in D, radiodurans and carry h omologous sequences for replacement recombination in the D, radiodurans chr omosome, The resulting integration vectors were used to study expression of reporter genes fused to a number of putative promoters that were amplified from the D, radiodurans R1 genome. Further analysis of these and other put ative promoters was performed by Northern hybridization and primer extensio n experiments. In contrast to previous reports, the -10 and -35 regions of these promoters resembled the sigma (70) consensus sequence of E., coli.