THE C-TERMINAL REGION OF THE ALPHA-SUBUNIT OF ESCHERICHIA-COLI RNA-POLYMERASE IS REQUIRED FOR TRANSCRIPTIONAL ACTIVATION OF THE FLAGELLAR LEVEL-II OPERONS BY THE FLHD FLHC COMPLEX/

A number of transcription activators have been found to activate trans cription via protein-protein contact between RNA polymerase alpha subu nits and transcription factors; they are classified as class I factors . In this report, we demonstrate that the FlhD/FlhC complex, a transcr iption activator of the Escherichia coli flagellar regulon, requires t he C-terminal domain of the RNA polymerase alpha subunit for transcrip tion activation. We conclude that FlhD/FlhC is a class I transcription factor.