title: Localization of L11 protein on the ribosome and elucidation of its involvement in EF-G-dependent translocation.
abstract: L11 protein is located at the base of the L7/L12 stalk of the 50 S subunit of the Escherichia coli ribosome. Because of the flexible nature of the region, recent X-ray crystallographic studies of the 50 S subunit failed to locate the N-terminal domain of the protein. We have determined the position of the complete L11 protein by comparing a three-dimensional cryo-EM reconstruction of the 70 S ribosome, isolated from a mutant lacking ribosomal protein L11, with the three-dimensional map of the wild-type ribosome. Fitting of the X-ray coordinates of L11-23 S RNA complex and EF-G into the cryo-EM maps combined with molecular modeling, reveals that, following EF-G-dependent GTP hydrolysis, domain V of EF-G intrudes into the cleft between the 23 S ribosomal RNA and the N-terminal domain of L11 (where the antibiotic thiostrepton binds), causing the N-terminal domain to move and thereby inducing the formation of the arc-like connection with the G' domain of EF-G. The results provide a new insight into the mechanism of EF-G-dependent translocation.
authors.affiliation: Wadsworth Center, Empire State Plaza, Albany, NY 12201-0509, USA. agrawal@wadsworth.org
authors.forename: R K
authors.initials: RK
authors.lastname: Agrawal
authors.forename: J
authors.initials: J
authors.lastname: Linde
authors.forename: J
authors.initials: J
authors.lastname: Sengupta
authors.forename: K H
authors.initials: KH
authors.lastname: Nierhaus
authors.forename: J
authors.initials: J
authors.lastname: Frank
mesh_terms: D020285:Cryoelectron Microscopy; D018360:Crystallography, X-Ray; D004926:Escherichia coli / Q000737:chemistry / Q000235:genetics; D029968:Escherichia coli Proteins; D017353:Gene Deletion; D006160:Guanosine Triphosphate / Q000378:metabolism; D006868:Hydrolysis; D008958:Models, Molecular; D020653:Peptide Elongation Factor G / Q000378:metabolism*; D011485:Protein Binding; D020836:Protein Structure, Quaternary; D017434:Protein Structure, Tertiary; D021122:Protein Subunits; D012269:Ribosomal Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure; D012270:Ribosomes / Q000737:chemistry* / Q000378:metabolism / Q000648:ultrastructure*
chemical_list: D029968:Escherichia coli Proteins; D020653:Peptide Elongation Factor G; D021122:Protein Subunits; D012269:Ribosomal Proteins; C027624:ribosomal protein L11; C043816:ribosomal protein L23, E coli; D006160:Guanosine Triphosphate