E. coli pH regulation Melibiose Glutamate

No abstract

The phs mutation, which causes a pleiotropic growth defect, has been mapped and shown to be an allele of rpoA, the gene for the a subunit of RNA polymerase. The mutation is shown to cause a transcription defect in the arabinose operon, araBAD.

Using segments of the Escherichia coli rpoB and rpoC genes as heterologous probes, we have identified and cloned an 8.3 kb PstI fragment from the Staphylococcus aureus genome containing the rpoB and rpoC genes, which respectively encode the p and p' subunits of DNA-directed RNA polymerase. This region is almost certainly equivalent to the riflocus, located near tofus at interval 12/13 on the S. aureus linkage map. Limited DNA sequencing revealed the gene order rpoB-rpoC (transcribed from left to right) and identified the rplL gene, encoding ribosomal protein L7/L12, upstream of rpoB. This and other evidence suggests that the rpoBC genes of S. aureus form part of a large gene cluster encoding components of the transcription and translation apparatus which is well-conserved in other eubacteria.