SNAP annotations: PDB entry 1zo1

PDB-id

1zo1; DSSR-derived features in text and JSON formats; DNAproDB

Class

translation-RNA

Method

cryo-EM (13.8 Å)

Summary

If2, if1, and trna fitted to cryo-EM data of e. coli 70s initiation complex

Reference

Allen GS, Zavialov A, Gursky R, Ehrenberg M, Frank J (2005): "The Cryo-EM Structure of a Translation Initiation Complex from Escherichia coli." Cell(Cambridge,Mass.), 121, 703-712. doi: 10.1016/j.cell.2005.03.023.

Abstract

The 70S ribosome and its complement of factors required for initiation of translation in E. coli were purified separately and reassembled in vitro with GDPNP, producing a stable initiation complex (IC) stalled after 70S assembly. We have obtained a cryo-EM reconstruction of the IC showing IF2*GDPNP at the intersubunit cleft of the 70S ribosome. IF2*GDPNP contacts the 30S and 50S subunits as well as fMet-tRNA(fMet). IF2 here adopts a conformation radically different from that seen in the recent crystal structure of IF2. The C-terminal domain of IF2 binds to the single-stranded portion of fMet-tRNA(fMet), thereby forcing the tRNA into a novel orientation at the P site. The GTP binding domain of IF2 binds to the GTPase-associated center of the 50S subunit in a manner similar to EF-G and EF-Tu. Additionally, we present evidence for the localization of IF1, IF3, one C-terminal domain of L7/L12, and the N-terminal domain of IF2 in the initiation complex.