Structural highlights
Function
[IF1_ECOLI] No specific function has so far been attributed to this initiation factor; however, it seems to stimulate more or less all the activities of the other two initiation factors, IF-2 and IF-3.[1] [IF2_ECOLI] One of the essential components for the initiation of protein synthesis. Protects formylmethionyl-tRNA from spontaneous hydrolysis and promotes its binding to the 30S ribosomal subunits. Also involved in the hydrolysis of GTP during the formation of the 70S ribosomal complex.[HAMAP-Rule:MF_00100_B]
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
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.
The cryo-EM structure of a translation initiation complex from Escherichia coli.,Allen GS, Zavialov A, Gursky R, Ehrenberg M, Frank J Cell. 2005 Jun 3;121(5):703-12. PMID:15935757[2]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Pon CL, Wittmann-Liebold B, Gualerzi C. Structure--function relationships in Escherichia coli initiation factors. II. Elucidation of the primary structure of initiation factor IF-1. FEBS Lett. 1979 May 1;101(1):157-60. PMID:376343
- ↑ Allen GS, Zavialov A, Gursky R, Ehrenberg M, Frank J. The cryo-EM structure of a translation initiation complex from Escherichia coli. Cell. 2005 Jun 3;121(5):703-12. PMID:15935757 doi:10.1016/j.cell.2005.03.023
