Allosteric activation of RhlB by RNase E induces partial duplex opening in substrate RNA

Frontiers in Molecular Biosciences

Molecular Biosciences

Laura Raschke¹  Heidi Zetzsche¹  Boris Fürtig² 

[1] Center for Biomolecular Magnetic Resonance (BMRZ), Institute for Organic Chemistry and Chemical Biology, Johann Wolfgang Goethe-Universität, Frankfurt, Germany;null;

关键词: RNA folding;    NMR spectroscopy;    RNA helicase;    real time NMR;    RNA dynamics;   

DOI  :  10.3389/fmolb.2023.1139919

 received in 2023-01-07, accepted in 2023-08-10,  发布年份 2023

来源: Frontiers

【 摘 要 】

The E. coli DEAD-Box helicase RhlB is responsible for ATP-dependent unwinding of structured mRNA to facilitate RNA degradation by the protein complex degradosome. The allosteric interaction with complex partner RNase E is necessary to stimulate both, RhlB’s ATPase and RNA unwinding activity to levels comparable with other DEAD-Box helicases. However, the structural changes of the helicase RhlB induced by binding of RNase E have not been characterized and how those lead to increased reaction rates has remained unclear. We investigated the origin of this activation for RNA substrates with different topologies. Using NMR spectroscopy and an RNA centered approach, we could show that RNase E binding increases the affinity of RhlB towards a subset of RNA substrates, which leads to increased ATP turnover rates. Most strikingly, our studies revealed that in presence of RNase E (694-790) RhlB induces a conformational change in an RNA duplex with 5’- overhang even in absence of ATP, leading to partial duplex opening. Those results indicate a unique and novel activation mode of RhlB among DEAD-Box helicases, as ATP binding is thought to be an essential prerequisite for RNA unwinding.

【 授权许可】

Unknown   
Copyright © 2023 Zetzsche, Raschke and Fürtig.