Essential structure ofE. colipromoter effect of spacer length between the two consensus sequences on promoter function

Abstract
A promoter with the consensus sequences(TTGACA and TATAAT) at −35 and −10 regions was constructed, and the distance between the two consensus sequences was independently altered at two restriction sites. In an in vitro transcription system, a maximum activity was observed at the spacer length of 17 base-pairs regardless of the sites of space adjustment. Evidence was also provided that the start point of transcription was fixed by the consensus sequence at the −10 region.