1G7R: X-RAY STRUCTURE OF TRANSLATION INITIATION FACTOR IF2/EIF5B

Citation:
Abstract
X-ray structures of the universal translation initiation factor IF2/eIF5B have been determined in three states: free enzyme, inactive IF2/eIF5B.GDP, and active IF2/eIF5B.GTP. The "chalice-shaped" enzyme is a GTPase that facilitates ribosomal subunit joining and Met-tRNA(i) binding to ribosomes in all three kingdoms of life. The conserved core of IF2/eIF5B consists of an N-terminal G domain (I) plus an EF-Tu-type beta barrel (II), followed by a novel alpha/beta/alpha-sandwich (III) connected via an alpha helix to a second EF-Tu-type beta barrel (IV). Structural comparisons reveal a molecular lever, which amplifies a modest conformational change in the Switch 2 region of the G domain induced by Mg(2+)/GTP binding over a distance of 90 A from the G domain active center to domain IV. Mechanisms of GTPase function and ribosome binding are discussed.
PDB ID: 1G7RDownload
MMDB ID: 15186
PDB Deposition Date: 2000/11/14
Updated in MMDB: 2007/10
Experimental Method:
x-ray diffraction
Resolution: 2.2  Å
Source Organism:
Similar Structures:
Biological Unit for 1G7R: monomeric; determined by author
Molecular Components in 1G7R
Label Count Molecule
Protein (1 molecule)
1
Translation Initiation Factor If2/eif5b(Gene symbol: MTH_RS01190)
Molecule annotation
* Click molecule labels to explore molecular sequence information.

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