Overproduced bacteriophage T4 gene 33 protein binds RNA polymerase

Bacteriophage T4 gene 33 protein (gp33), which is required for viral late transcription, has been overproduced. The purified gp33 binds to RNA polymerase core from uninfected or T4-infected Escherichia coli, but the major E. coli transcription initiation factor, sigma 70, competed effectively for this binding.