4UJC

mammalian 80S HCV-IRES initiation complex with eIF5B POST-like state

This is a non-PDB format compatible entry.

Summary for 4UJC

• Entry DOI: 10.2210/pdb4ujc/pdb
• Related: 4UPW 4UPX 4UPY
• EMDB information: 2683
• Descriptor: TRNA, 60S RIBOSOMAL PROTEIN L5, 60S RIBOSOMAL PROTEIN L6, ... (85 entities in total)
• Functional Keywords: ribosome, translation initiation, hepatitis c virus internal ribosome entry site, eukaryotic initiation factor 5b
• Biological source: ORYCTOLAGUS CUNICULUS (RABBIT); More
• Total number of polymer chains: 83
• Total formula weight: 4041153.40

Authors

Yamamoto, H.,Unbehaun, A.,Loerke, J.,Behrmann, E.,Marianne, C.,Burger, J.,Mielke, T.,Spahn, C.M.T. (deposition date: 2014-06-18, release date: 2014-07-30, Last modification date: 2019-12-18)

Primary citation

Yamamoto, H.,Unbehaun, A.,Loerke, J.,Behrmann, E.,Collier, M.,Burger, J.,Mielke, T.,Spahn, C.M.T.
Structure of the Mammalian 80S Initiation Complex with Initiation Factor 5B on Hcv-Ires RNA.
Nat.Struct.Mol.Biol., 21:721-, 2014

PubMed Abstract: The universally conserved eukaryotic initiation factor (eIF) 5B, a translational GTPase, is essential for canonical translation initiation. It is also required for initiation facilitated by the internal ribosomal entry site (IRES) of hepatitis C virus (HCV) RNA. eIF5B promotes joining of 60S ribosomal subunits to 40S ribosomal subunits bound by initiator tRNA (Met-tRNAi(Met)). However, the exact molecular mechanism by which eIF5B acts has not been established. Here we present cryo-EM reconstructions of the mammalian 80S-HCV-IRES-Met-tRNAi(Met)-eIF5B-GMPPNP complex. We obtained two substates distinguished by the rotational state of the ribosomal subunits and the configuration of initiator tRNA in the peptidyl (P) site. Accordingly, a combination of conformational changes in the 80S ribosome and in initiator tRNA facilitates binding of the Met-tRNAi(Met) to the 60S P site and redefines the role of eIF5B as a tRNA-reorientation factor.

PubMed: 25064512
DOI: 10.1038/NSMB.2859

Experimental method

ELECTRON MICROSCOPY (9.5 Å)