FIG. 1.

Promoter elements of the icsP promoter and schematic representation of the truncated promoter series. (A) Angled arrows represent the icsP transcription start site (+1), determined previously (8). The hexamers at positions −10 and −35 are boxed and shown in boldface type. The translation start site is outlined by an arrow. The truncated promoters are drawn to scale, and the numbers represent the upstream boundary of the icsP promoter, relative to the transcription start site (+1). The promoter fragments represented are found in pHJW20, pJS01, pJS02, pDH01, pJS04, pHJW34, pHJW35, and pHJW36. (B) Solid black arrows represent the relative position and orientation of the nine VirB binding sites identified within the promoter fragments used in this work. In each case, the match to consensus sequence 5′-(A/G)(A/T)G(G)AAAT-3′ (30, 32) is given.