Mechanism of action of bacterial transcription terminator rho

Abstract

The bacterial transcription terminator, Rho, is a well conserved protein among the prokaryotes. It was discovered about 50 years back and still, a significant number of the researchers across the globe are actively engaged in understanding the function of this protein. Rho is a hexameric RNA-dependent helicase that dislodges transcribing RNA polymerase. Its binding site on the RNA is quite degenerated, and thereby many mRNAs are its target, which leads to regulation of a wide range of operons by the Rho-dependent termination. This genome-wide control by Rho brings in pleotropic effects in the cell physiology and hence if this termination process is perturbed, many biological processes get directly affected. In this review, we will cover various mechanistic aspects of the Rho-dependent transcription termination highlighting the significant contributions made by us over the last 12 years. We shall also describe some aspects of the cell physiology that is under the control of this factor-dependent termination process. The review includes the biochemistry and the structural analyses of the Rho, its mechanism of action, its regulation by other cellular factors and briefly cellular events controlled by this protein.