Enzyme assernbly promoter recognition, activator binding Possible catalytic subunits a BBo做 le unknown (not needed in vitro 15115511kDa a 38.5kDa Promoter →O(3290kDa specificity The E coli rna polymerase holoenzyme consists of six Subunits: a2BBooThe E. coli RNA polymerase holoenzyme consists of six subunits: a2bb’ s. Possible catalytic subunits Promoter specificity Enzyme assembly, promoter recognition, activator binding Role unknown (not needed in vitro) 36.5 kDa 151 155 11 kDa (32-90 kDa)