Format

Send to

Choose Destination
Cell. 2013 Mar 28;153(1):166-77. doi: 10.1016/j.cell.2013.02.037.

An RNA degradation machine sculpted by Ro autoantigen and noncoding RNA.

Author information

1
Department of Cell Biology, Yale School of Medicine, New Haven, CT 06510, USA.

Abstract

Many bacteria contain an ortholog of the Ro autoantigen, a ring-shaped protein that binds noncoding RNAs (ncRNAs) called Y RNAs. In the only studied bacterium, Deinococcus radiodurans, the Ro ortholog Rsr functions in heat-stress-induced ribosomal RNA (rRNA) maturation and starvation-induced rRNA decay. However, the mechanism by which this conserved protein and its associated ncRNAs act has been obscure. We report that Rsr and the exoribonuclease polynucleotide phosphorylase (PNPase) form an RNA degradation machine that is scaffolded by Y RNA. Single-particle electron microscopy, followed by docking of atomic models into the reconstruction, suggests that Rsr channels single-stranded RNA into the PNPase cavity. Biochemical assays reveal that Rsr and Y RNA adapt PNPase for effective degradation of structured RNAs. A Ro ortholog and ncRNA also associate with PNPase in Salmonella Typhimurium. Our studies identify another ribonucleoprotein machine and demonstrate that ncRNA, by tethering a protein cofactor, can alter the substrate specificity of an enzyme.

PMID:
23540697
PMCID:
PMC3646564
DOI:
10.1016/j.cell.2013.02.037
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for Elsevier Science Icon for PubMed Central
Loading ...
Support Center