The UP element of the promoter for the flagellin gene, hag, stimulates transcription from both SigD- and SigA-dependent promoters in Bacillus subtilis

DNA sequences upstream (UP element) of the core promoter (-10, -35 region) of the Bacillus subtilis flagellin gene hag stimulate transcription in vivo and in vitro. We constructed a number of hybrids, placing the UP element of hagp upstream of the core of one SigD-dependent (fliDp) and two SigA-dependent (tmsp, vegp) B. subtilis promoters. The hybrid promoters were fused to a lacZ reporter gene and their activity tested in vivo. The presence of the UP module enhanced transcription at both types of promoters. We conclude that the hagp UP sequence can act as a promoter module independently of the core sequence.