Mapping of the glucose dehydrogenase gene in Bacillus subtilis

A 4.0-kilobase DNA fragment containing the developmentally regulated gene for glucose dehydrogenase (gdh) from Bacillus subtilis was incorporated into the plasmid pGX345, which contains a marker conferring chloramphenicol resistance (cat). The resistance marker of the resulting integration vector was used to map the gdh gene on the B. subtilis chromosome. Using PBS1 transduction, the gene order was determined to be aroI cat (gdh) mtlB dal. The cat (gdh) marker was also cotransformable with mtlB. The genetic location of the gdh gene established by this indirect method was confirmed by the fact that the original phage lambda EF2, containing a 10-kilobase B. subtilis DNA fragment from which the 4-kilobase gdh region had been subcloned, also contained the mtlB gene.