TY - JOUR
T1 - Elongation factor 4 remodels the A-site tRNA on the ribosome
AU - Gagnon, Matthieu G.
AU - Lin, Jinzhong
AU - Steitz, Thomas A.
N1 - Funding Information:
We thank Yury Polikanov (University of Illinois at Chicago) for valuable discussions, suggestions, and critical reading of the manuscript. We thank Robert Grodzicki for preparing fMet-tRNAfMet and PhetRNAPhe. We also thank the staffs of the Advanced Photon Source beamline 24-ID for help with data collection and the Richards Center facility at Yale University for computational support. This work was supported by National Institutes of Health Grant GM022778 (to T.A.S.). This work is based upon research conducted at the Northeastern Collaborative Access Team beamlines, which are funded by the National Institute of General Medical Sciences from the National Institutes of Health (Grant P41 GM103403). The Pilatus 6M detector on 24-ID-C beamline is funded by NIH-ORIP HEI Grant S10 RR029205. This research used resources of the Advanced Photon Source, a US Department of Energy (DOE) Office of Science User Facility operated for the DOE Office of Science by Argonne National Laboratory under Contract DE-AC02-06CH11357.
PY - 2016/5/3
Y1 - 2016/5/3
N2 - During translation, a plethora of protein factors bind to the ribosome and regulate protein synthesis. Many of those factors are guanosine triphosphatases (GTPases), proteins that catalyze the hydrolysis of guanosine 5-triphosphate (GTP) to promote conformational changes. Despite numerous studies, the function of elongation factor 4 (EF-4/LepA), a highly conserved translational GTPase, has remained elusive. Here, we present the crystal structure at 2.6-Ã resolution of the Thermus thermophilus 70S ribosome bound to EF-4 with a nonhydrolyzable GTP analog and A-, P-, and E-site tRNAs. The structure reveals the interactions of EF-4 with the A-site tRNA, including contacts between the C-terminal domain (CTD) of EF-4 and the acceptor helical stem of the tRNA. Remarkably, EF-4 induces a distortion of the A-site tRNA, allowing it to interact simultaneously with EF-4 and the decoding center of the ribosome. The structure provides insights into the tRNA-remodeling function of EF-4 on the ribosome and suggests that the displacement of the CCA-end of the A-site tRNA away from the peptidyl transferase center (PTC) is functionally significant.
AB - During translation, a plethora of protein factors bind to the ribosome and regulate protein synthesis. Many of those factors are guanosine triphosphatases (GTPases), proteins that catalyze the hydrolysis of guanosine 5-triphosphate (GTP) to promote conformational changes. Despite numerous studies, the function of elongation factor 4 (EF-4/LepA), a highly conserved translational GTPase, has remained elusive. Here, we present the crystal structure at 2.6-Ã resolution of the Thermus thermophilus 70S ribosome bound to EF-4 with a nonhydrolyzable GTP analog and A-, P-, and E-site tRNAs. The structure reveals the interactions of EF-4 with the A-site tRNA, including contacts between the C-terminal domain (CTD) of EF-4 and the acceptor helical stem of the tRNA. Remarkably, EF-4 induces a distortion of the A-site tRNA, allowing it to interact simultaneously with EF-4 and the decoding center of the ribosome. The structure provides insights into the tRNA-remodeling function of EF-4 on the ribosome and suggests that the displacement of the CCA-end of the A-site tRNA away from the peptidyl transferase center (PTC) is functionally significant.
KW - Elongation factor 4
KW - Protein-RNA interactions
KW - Remodeling
KW - Ribosome
KW - TRNA
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U2 - 10.1073/pnas.1522932113
DO - 10.1073/pnas.1522932113
M3 - Article
C2 - 27092003
AN - SCOPUS:84965115135
SN - 0027-8424
VL - 113
SP - 4994
EP - 4999
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
IS - 18
ER -