Discovery of a ptsHI operon, which includes a third gene (ptsT), in the thermophile Bacillus stearothermophilus.

摘要: The discovery of a ptsHl operon in Bacillus stearothermophilus XL-65-6 coupled with our previous report cel (Lai Ingram, J Bacteriol 175, 6441-6450, 1993) demonstrates that this thermophilic organism contains all the genes required for cellobiose uptake by phosphoenolpyruvate-dependent phosphotransferase system (PTS). Genes encoding two general PTS proteins, HPr (ptsH) and enzyme l (ptsl), were cloned sequenced. These form an which includes third small gene (ptsT) unknown function (encoded product M r 18428). Both ptsH ptsl expressed at high levels from single plasmid Escherichia coli complemented corresponding host mutations. Although translated sequences these similar to homologues Gram-positive mesophiles (64-77% identity), B. products unusual having higher predicted pi fewer negatively charged amino acid residues. Enzyme I also contained more alanine leucine than mesophilic counterparts. Interestingly, ptsT inhibited growth E. mutants 37°C. No such inhibition was observed during incubation lower temperature (30°C) or DH5α, is wild-type ptsl. translation proportion basic acids (27%) had pl (pH 117), properties bacterial histone-like but did not exhibit homology any current database. Regions upstream downstream contain subtilis ptsG wapA (wall-associated protein), respectively.