title: Structure of the GTP Form of Elongation Factor 4 (EF4) Bound to the Ribosome.
abstract: Elongation factor 4 (EF4) is a member of the family of ribosome-dependent translational GTPase factors, along with elongation factor G and BPI-inducible protein A. Although EF4 is highly conserved in bacterial, mitochondrial, and chloroplast genomes, its exact biological function remains controversial. Here we present the cryo-EM reconstitution of the GTP form of EF4 bound to the ribosome with P and E site tRNAs at 3.8-Å resolution. Interestingly, our structure reveals an unrotated ribosome rather than a clockwise-rotated ribosome, as observed in the presence of EF4-GDP and P site tRNA. In addition, we also observed a counterclockwise-rotated form of the above complex at 5.7-Å resolution. Taken together, our results shed light on the interactions formed between EF4, the ribosome, and the P site tRNA and illuminate the GTPase activation mechanism at previously unresolved detail.
authors.affiliation: From the Institute of Molecular and Cell Biology, The Agency for Science, Technology and Research (A*STAR), 61 Biopolis Drive, 138673 Singapore, the School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, 637551 Singapore, and.
authors.forename: Veerendra
authors.initials: V
authors.lastname: Kumar
authors.affiliation: the School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, 637551 Singapore, and.
authors.forename: Rya
authors.initials: R
authors.lastname: Ero
authors.affiliation: the School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, 637551 Singapore, and.
authors.forename: Tofayel
authors.initials: T
authors.lastname: Ahmed
authors.affiliation: the School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, 637551 Singapore, and.
authors.forename: Kwok Jian
authors.initials: KJ
authors.lastname: Goh
authors.affiliation: the School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, 637551 Singapore, and.
authors.forename: Yin
authors.initials: Y
authors.lastname: Zhan
authors.affiliation: the School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, 637551 Singapore, and the Institute of Structural Biology, Nanyang Technological University, 636921 Singapore.
authors.forename: Shashi
authors.initials: S
authors.lastname: Bhushan
authors.affiliation: From the Institute of Molecular and Cell Biology, The Agency for Science, Technology and Research (A*STAR), 61 Biopolis Drive, 138673 Singapore, the School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, 637551 Singapore, and the Institute of Structural Biology, Nanyang Technological University, 636921 Singapore ygao@ntu.edu.sg.
authors.forename: Yong-Gui
authors.initials: YG
authors.lastname: Gao
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry*; D020134:Catalytic Domain; D020285:Cryoelectron Microscopy; D020963:GTP Phosphohydrolase-Linked Elongation Factors / Q000737:chemistry*; D006153:Guanosine Diphosphate / Q000737:chemistry; D006160:Guanosine Triphosphate / Q000737:chemistry; D006860:Hydrogen Bonding; D006868:Hydrolysis; D008958:Models, Molecular; D011485:Protein Binding; D054681:Ribosome Subunits, Large, Bacterial / Q000737:chemistry*; D054680:Ribosome Subunits, Small, Bacterial / Q000737:chemistry*; D016963:Thermus thermophilus
chemical_list: D001426:Bacterial Proteins; D006153:Guanosine Diphosphate; D006160:Guanosine Triphosphate; D020963:GTP Phosphohydrolase-Linked Elongation Factors
keywords: EF4; LepA; cryo-EM; ribosome structure; translation; translation elongation factor; translational GTPase factor; translocation