Interactions among CII protein, RNA polymerase and the   PRE promoter: contacts between RNA polymerase and the -35 region of PRE are identical in the presence and absence of CII protein

• Published in: Nucleic acids research 2004-02, Vol.32 (3), p.1083-1090
• Main Author: Marr, M. T.
• Format: Article
• Language: English
• ISSN: 1362-4962; 0305-1048; 1362-4962
• DOI: 10.1093/nar/gkh261

The DNA recognition sequence for the transcriptional activator, CII protein, which is critical for lysogenization by bacteriophage [lambda], overlaps the -35 region of the PRE promoter. Data presented here show that activation by CII does not change the pattern of cleavage of the -35 region of PRE by iron (S)-1-(p-bromoacetamidobenzyl)-EDTA (Fe-BABE) conjugated to the [sigma] subunit of RNA polymerase (RNAP). Thus, the overall interaction between [sigma] and the -35 region of PRE is not significantly altered by CII. Therefore, the effects of the activator on RNAP binding to the promoter and formation of open complexes do not reflect a large-scale qualitative change in the nature of the interaction between RNAP and promoter DNA. The ability of CII to stimulate lysogenization is reduced in the presence of plasmid-borne rpoA variants encoding alanine substitutions at several positions in the C-terminal domain of the [alpha] subunit. However, it has not been possible to identify residues that directly affect the interaction between the activator and RNA polymerase.