Essential structure of E. coli promoter II. Effect of the sequences around the RNA start point on promoter function.

Starting from a synthetic E. coli promoter with the consensus sequences at -35 and -10 regions, a sequence CAT frequently occurred in the RNA start points of natural promoters was introduced in the downstream of the consensus sequences, and the sequences around the RNA start points as well as the relative positions of CAT from the consensus sequences were altered. Analysis of the RNA start points and strength of these synthetic promoters in an in vitro transcription system provided evidence that the RNA start point was principally fixed by distance from the -10 consensus sequence (TATAAT). Neither the promoter strength nor the RNA start point was significantly influenced by the CAT sequence. The sequences around the RNA start points rather seemed to exert influence on the response of promoter to temperature and salts.