Regulatory 3' Untranslated Regions of Bacterial mRNAs

Abstract

The untranslated regions (UTRs) of mRNA contain important features that are relevant to the post-transcriptional and translational regulation of gene expression. Most studies of bacterial UTRs have focused on the 5'regions; however, 3'UTRs have recently emerged as a new class of post-transcriptional regulatory elements. 3'UTRs were found to regulate the decay and translation initiation in their own mRNAs. In addition, 3'UTRs constitute a rich reservoir of small regulatory RNAs, regulating target gene expression. In the current review, we describe several recently discovered examples of bacterial regulatory 3'UTRs, discuss their modes of action, and illustrate how they facilitate gene regulation in various environments.

Keywords: 3′untranslated region; bacteria; mRNA decay; mRNA translation initiation; post-transcriptional regulation.

FIGURE 1

Regulatory pathways of 3′UTRs in bacteria. An mRNA usually contains three regions, the 5′UTR, the coding sequence (CDS), and the 3′UTR. (A) A 3′UTR is recognized and cleaved by ribonuclease to initiate mRNA decay. (B) A 3′UTR-derived sRNA regulates expression of its target gene. (C) A 3′UTR functions as the target of regulatory sRNA, resulting in protection of the 3′UTR from degradation or promoting its degradation. (D) A 3′ UTR interacts with the 5′ region of its own gene, potentially affecting mRNA stability and translational initiation.