Trans-translation exposed: understanding the structures and functions of tmRNA-SmpB

• Main Authors: Emmanuel eGIUDICE, Kevin eMACE, Reynald eGILLET
• Format: Article
• Language: English
• Published: Frontiers Media S.A. 2014-03-01
• Series: Frontiers in Microbiology
• Subjects: ribosome; Structure; tmRNA; trans-translation; SmpB
• Online Access: http://journal.frontiersin.org/Journal/10.3389/fmicb.2014.00113/full

Ribosome stalling is a serious issue for cell survival. In bacteria, the primary rescue system is trans-translation, performed by tmRNA and its protein partner small protein B (SmpB). Since its discovery almost 20 years ago, biochemical, genetic, and structural studies have paved the way to a better understanding of how this sophisticated process takes place at the cellular and molecular levels. Here we describe the molecular details of trans-translation, with special mention of recent cryo-electron microscopy and crystal structures that have helped explain how the huge tmRNA-SmpB complex targets and delivers stalled ribosomes without interfering with canonical translation.