Fig. 2.
Recognition of the aveRp promoter by σhrdB-containing RNA polymerase. (A) Comparison of the putative aveRp promoter of S. avermitilis with rrnD-p2 and dagA-p4 of S. coelicolor. The conserved nucleotides within the -10 and -35 regions as well as transcription initiation sites are marked in bold. (B) In vitro transcription assay of the aveRp promoter by RNA polymerase containing σhrdB (EσhrdB). The promoter of the rrnD-homologous gene in S. avermitilis was used as a positive control. In all lanes, the EσhrdB holoenzyme was reconstituted by 0.25 pmol E. coli RNA polymerase core enzyme (EPICENTRE) with the indicated amounts of σhrdB. The ratio of sigma factor to the core RNA polymerase is indicated.