Activation of transcription by guanosine 5' diphosphate,3' diphosphate, transfer ribonucleic acid, and a novel protein from Escherichia coli

A protein factor (TFms) that is required for ppGpp to stimulate RNA synthesis has been purified from an eluate of crude ribosomes. TFms also has the capacity to stimulate RNA synthesis without ppGpp present. Under standard conditions the action of TFms and ppGpp requires uncharged tRNA. TFms and ppGpp act at inhibition to promote the formation of rifampicin resistant or poly(rI) resistant preinitiation complexes. In the presence of rifampicin or poly(rI), tRNA is no longer required. With λh80dlacPs DNA as template, ppGpp together with TFms stimulated lac specific RNA synthesis to a much greater extent than total RNA synthesis. Similarly, with λpgal DNA, ppGpp together with TFms stimulated gal RNA synthesis to a much greater extent than total RNA synthesis. The stimulation of both lac and gal RNA synthesis was increased in the presence of cyclic AMP receptor and cyclic AMP.