- M Carty: E.I. du Pont de Nemours, Central Research and Development Division, Wilmington, DE 19880-0328.
We show that transcription originating at the gyrA promoter of Escherichia coli is less subject to termination at the lambda Toop terminator (22% read-through) than is transcription originating from either the galOP (1% read-through) or topA (3% read-through) control regions. Furthermore, termination of the gyrA transcripts decreases (60% read-through) upon relaxation of the template DNA. We believe that events related to stimulation of transcription at the gyrA promoter by DNA relaxation are responsible for the enhanced terminator read-through.