X-ray Structure of Translation Initiation Factor eIF2gamma: IMPLICATIONS FOR tRNA AND eIF2alpha BINDING.
Roll-Mecak, A., Alone, P., Cao, C., Dever, T.E., Burley, S.K.(2004) J Biol Chem 279: 10634-10642
- PubMed: 14688270
- DOI: https://doi.org/10.1074/jbc.M310418200
- Primary Citation of Related Structures:
1S0U - PubMed Abstract:
The x-ray structure of the gamma-subunit of the heterotrimeric translation initiation factor eIF2 has been determined to 2.4-A resolution. eIF2 is a GTPase that delivers the initiator Met-tRNA to the P site on the small ribosomal subunit during a rate-limiting initiation step in translation. The structure of eIF2gamma closely resembles that of EF1A.GTP, consisting of an N-terminal G domain followed by two beta-barrels arranged in a closed configuration with domain II packed against the G domain in the vicinity of the Switch regions. The G domain of eIF2gamma has an unusual zinc ribbon motif, not previously found in other GTPases. Structure-based site-directed mutagenesis was used to identify two adjacent features on the surface of eIF2gamma that bind the alpha-subunit and Met-tRNA(i)(Met), respectively. These structural, biochemical, and genetic results provide new insights into eIF2 ternary complex assembly.
Organizational Affiliation:
Laboratories of Molecular Biophysics, The Rockefeller University, New York, New York 10021, USA.