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Structure of a human 48 S translational initiation complex

DOI: 10.1126/science.aba4904 DOI Help

Authors: Jailson Brito Querido (MRC Laboratory of Molecular Biology) , Masaaki Sokabe (University of California, Davis) , Sebastian Kraatz (MRC Laboratory of Molecular Biology) , Yuliya Gordiyenko (MRC Laboratory of Molecular Biology) , J. Mark Skehel (MRC Laboratory of Molecular Biology) , Christopher S. Fraser (University of California, Davis) , Venki Ramakrishnan (MRC Laboratory of Molecular Biology)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Science , VOL 369 , PAGES 1220 - 1227

State: Published (Approved)
Published: September 2020
Diamond Proposal Number(s): 17434

Abstract: A key step in translational initiation is the recruitment of the 43S preinitiation complex by the cap-binding complex [eukaryotic initiation factor 4F (eIF4F)] at the 5′ end of messenger RNA (mRNA) to form the 48S initiation complex (i.e., the 48S). The 48S then scans along the mRNA to locate a start codon. To understand the mechanisms involved, we used cryo–electron microscopy to determine the structure of a reconstituted human 48S. The structure reveals insights into early events of translation initiation complex assembly, as well as how eIF4F interacts with subunits of eIF3 near the mRNA exit channel in the 43S. The location of eIF4F is consistent with a slotting model of mRNA recruitment and suggests that downstream mRNA is unwound at least in part by being “pulled” through the 40S subunit during scanning.

Subject Areas: Biology and Bio-materials, Chemistry

Diamond Offline Facilities: Electron Bio-Imaging Centre (eBIC)
Instruments: Krios II-Titan Krios II at Diamond

Added On: 07/01/2021 11:38

Discipline Tags:

Biochemistry Genetics Chemistry Structural biology Life Sciences & Biotech

Technical Tags:

Microscopy Electron Microscopy (EM) Cryo Electron Microscopy (Cryo EM)