Translation initiation factor 2 alters transcriptional selectivity of Escherichia coli ribonucleic acid polymerase

Preparations of translation initiation factor IF-2 strongly stimulate the production of rRNA by Escherichia coli RNA polymerase but have little effect on the synthesis of other RNA species. The factor alters the sedimentation characteristics of RNA polymerase holoenzyme. We suggest a mechanism by which IF-2 alters the pattern of transcriptional selectivity of RNA polymerase.