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Structure and conformational dynamics of biologically important RNAs


EMSL Project ID
51232

Abstract


RNA’s remarkable functional diversity is conferred by its ability to adopt a seemingly endless variety of structures and undergo programmed conformational dynamics. The emergence of cryo-EM as a premier structural biology tool suggests it could be applied to understand RNA structure, but cryo-EM studies of discrete folded RNA domains have been sparse. We propose to study two biologically important folded RNA elements using high-resolution cryo-EM. Both targets have complex 3-D structures and undergo conformational dynamics that confer unique function, but they have eluded crystallization for decades.

Aim 1 is to solve the structure of the complete group I self-splicing intron from Tetrahymena thermophila. While its core structure has been solved, the full structure with “auxiliary domains” has not (Stahley and Strobel 2006). Likewise, while misfolded intermediates have been characterized biochemically, these remain structurally mysterious (Russell, Das et al. 2006). Aim 2 is to solve the structure of the tRNA-like structure (TLS) found at the 3? end of the Brome Mosaic Virus (BMV) genome. This RNA ‘tricks’ host cell aminoacyl tRNA synthetase into adding an amino acid onto the 3? end of the genome (Rao and Cheng Kao 2015). How it mimics tRNA is unknown, as is how it coordinates other viral processes such as replication and translation.

Success in these projects will give new insight into these RNAs and will test the use of cryo-EM on RNA-only targets. Thus, the methods we develop and lessons we learn will have long-term impact on the entire field of RNA structural biology.

Project Details

Start Date
2019-12-20
End Date
2021-03-17
Status
Closed

Team

Principal Investigator

Jeffrey Kieft
Institution
University of Colorado Anschutz Medical Campus

Team Members

David Farrell
Institution
University of Colorado Anschutz Medical Campus

Steve Bonilla
Institution
University of Colorado Anschutz Medical Campus

Theo Humphreys
Institution
Oregon Health & Science University