Regulation of ribonucleic acid synthesis in Escherichia coli B/r: An analysis of a shift-up : III. Stable RNA synthesis rate and ribosomal RNA chain growth rate following a shift-up

Abstract

Following a nutritional shift-up, both the fraction of functioning RNA polymerase engaged in the synthesis of stable RNA, ψ s, and the ribosomal RNA chain growth rate, c s, increase within five minutes to near their final post-shift steady-state values. The increase in these two parameters is sufficient to account completely for the observed sudden increase in the rate of RNA accumulation. This implies that the control of stable RNA synthesis following a shift-up does not involve an activation of an inactive reserve of RNA polymerase or a burst of RNA polymerase synthesis, but rather results from a shift of RNA polymerase-transcribing messenger RNA genes to ribosomal and transfer RNA genes along with some increase in the stable RNA chain growth rate.