5MC6

Cryo-EM structure of a native ribosome-Ski2-Ski3-Ski8 complex from S. cerevisiae

This is a non-PDB format compatible entry.

Summary for 5MC6

• Entry DOI: 10.2210/pdb5mc6/pdb
• EMDB information: 3461
• Descriptor: 18S ribosomal RNA, 40S ribosomal protein S19-A, 40S ribosomal protein S20, ... (86 entities in total)
• Functional Keywords: cryo-em, ribosome, rna, helicase
• Biological source: Saccharomyces cerevisiae (strain ATCC 204508 / S288c); More
• Total number of polymer chains: 87
• Total formula weight: 3599383.47

Authors

Schmidt, C.,Kowalinski, E.,Shanmuganathan, V.,Defenouillere, Q.,Braunger, K.,Heuer, A.,Pech, M.,Namane, A.,Berninghausen, O.,Fromont-Racine, M.,Jacquier, A.,Conti, E.,Becker, T.,Beckmann, R. (deposition date: 2016-11-09, release date: 2017-01-18, Last modification date: 2019-12-11)

Primary citation

Schmidt, C.,Kowalinski, E.,Shanmuganathan, V.,Defenouillere, Q.,Braunger, K.,Heuer, A.,Pech, M.,Namane, A.,Berninghausen, O.,Fromont-Racine, M.,Jacquier, A.,Conti, E.,Becker, T.,Beckmann, R.
The cryo-EM structure of a ribosome-Ski2-Ski3-Ski8 helicase complex.
Science, 354:1431-1433, 2016

PubMed Abstract: Ski2-Ski3-Ski8 (Ski) is a helicase complex functioning with the RNA-degrading exosome to mediate the 3'-5' messenger RNA (mRNA) decay in turnover and quality-control pathways. We report that the Ski complex directly associates with 80S ribosomes presenting a short mRNA 3' overhang. We determined the structure of an endogenous ribosome-Ski complex using cryo-electron microscopy (EM) with a local resolution of the Ski complex ranging from 4 angstroms (Å) in the core to about 10 Å for intrinsically flexible regions. Ribosome binding displaces the autoinhibitory domain of the Ski2 helicase, positioning it in an open conformation near the ribosomal mRNA entry tunnel. We observe that the mRNA 3' overhang is threaded directly from the small ribosomal subunit to the helicase channel of Ski2, primed for ongoing exosome-mediated 3'-5' degradation.

PubMed: 27980209
DOI: 10.1126/science.aaf7520

Experimental method

ELECTRON MICROSCOPY (3.8 Å)