TY - JOUR
T1 - X-ray structures of the universal translation initiation factor IF2/eIF5B
T2 - Conformational changes on GDP and GTP binding
AU - Roll-Mecak, Antonina
AU - Cao, Chune
AU - Dever, Thomas E.
AU - Burley, Stephen K.
N1 - Funding Information:
At the Brookhaven National Laboratory National Synchrotron Light Source, we thank Drs. H. A. Lewis and L. Berman for access to Beamline X25, and Dr. K. R. Rajashankar for help using Beamline X9B. We thank Dr. J. Bonanno for his invaluable assistance with X-ray measurements, and Drs. L. Bellsolel, G. Blobel, B. Chait, X. C. Chen, R. C. Deo, C. U. T. Hellen, G. A. Petsko, D. Jeruzalmi, J. Kuriyan, C. Kielkopf, R. MacKinnon, S. K. Nair, T. V. Pestova, J. C. Padovan, and K. R. Rajashankar for many useful discussions. We thank H. Chen and G. He for technical help, and T. Niven for editorial assistance. We are grateful to K. L. Remo for providing yeast IF2/eIF5B plasmids, and Dr. J. N. Reeve for the gift of M. therm. genomic DNA. S. K. B. is an Investigator in the Howard Hughes Medical Institute. This work was supported by NIH grant GM61262 (to S. K. B.). A. R.-M. was supported by a National Science Foundation Graduate Fellowship and a Burroughs-Wellcome Fund Interfaces Training Grant to The Rockefeller University.
PY - 2000/11/22
Y1 - 2000/11/22
N2 - 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 β barrel (II), followed by a novel α/β/α-sandwich (III) connected via an α helix to a second EF-Tu-type β 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 Mg2+/GTP binding over a distance of 90 Å from the G domain active center to domain IV. Mechanisms of GTPase function and ribosome binding are discussed.
AB - 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 β barrel (II), followed by a novel α/β/α-sandwich (III) connected via an α helix to a second EF-Tu-type β 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 Mg2+/GTP binding over a distance of 90 Å from the G domain active center to domain IV. Mechanisms of GTPase function and ribosome binding are discussed.
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U2 - 10.1016/S0092-8674(00)00181-1
DO - 10.1016/S0092-8674(00)00181-1
M3 - Article
C2 - 11114334
AN - SCOPUS:0034703718
SN - 0092-8674
VL - 103
SP - 781
EP - 792
JO - Cell
JF - Cell
IS - 5
ER -