Structure-to-function relationships of RNA polymerases: recent advances in bacterial transcription termination

Transcription termination is a highly regulated step which sets boundaries between genes and maintains genome integrity. Defects in transcription termination will cause unexpected expression of downstream genes and traffic-jam of RNA polymerases with protein machineries. Termination occurs mainly in two types of mechanisms regarding whether it depends on molecular motor action, i.e. factor-dependent termination, or is induced solely by nucleic acid signals, i.e. intrinsic termination. In recent years, great efforts have been devoted to, and significant advances have been achieved in understanding the mechanisms of transcription termination. This review focuses on the topic of factor-dependent termination and intrinsic termination and highlights the recent progress in the structural and functional studies of RNA polymerases that are critical for transcription termination.