Pribnow Box Recognition and Melting by Escherichia coli RNA Polymerase

摘要: The core RNA polymerases from bacterial and eukaryotic cells, which are homologous in structure function (Allison et al. 1985; Biggs Ahearn 1987; Sweetser Darst 1989, 1991; Schultz 1993; Polyakov 1995), catalytically active chain elongation but incapable of promoter recognition specific initiation. Promoter-specific transcription initiation requires additional protein factors. In bacteria, by polymerase (RNAP) a single polypeptide known as σ factor, binds to RNAP form the holoenzyme (Burgess 1969; Travers Burgess 1969). One primary factor directs bulk during exponential growth. Specialized, alternative factors direct regulons unusual physiological or developmental conditions (reviewed Helmann Chamberlin 1988; Gross 1992). most comprise highly family proteins (Stragier Gribskov 1986) with four regions conserved amino acid sequence (Fig. 1; reviewed Lonetto Based on results genetic biochemical experiments, functions have been assigned some regions(summarized Fig. 1).