Download MendeleyX-Ray structures of the universal translation initiation factor IF2/eIF5B: conformational changes on GDP and GTP binding.
Roll-Mecak, A., Cao, C., Dever, T.E., Burley, S.K.(2000) Cell 103: 781-792
- PubMed: 11114334
- DOI: https://doi.org/10.1016/s0092-8674(00)00181-1
- Primary Citation of Related Structures:
1G7R, 1G7S, 1G7T - PubMed 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.
Organizational Affiliation:
Laboratories of Molecular Biophysics The Rockefeller University 10021, New York, NY 10021, USA.
