title: Identification of molecular interactions between P-site tRNA and the ribosome essential for translocation.
abstract: Translocation of the tRNA-mRNA complex is a fundamental step in the elongation cycle of protein synthesis. Our studies show that the ribosome can translocate a P-site-bound tRNA(Met) with a break in the phosphodiester backbone between positions 56 and 57 in the TPsiC-loop. We have used this fragmented P-site-bound tRNA(Met) to identify two 2'-hydroxyl groups at positions 71 and 76 in the 3'-acceptor arm that are essential for translocation. Crystallographic data show that the 2'-hydroxyl group at positions 71 and 76 contacts the backbone of 23S rRNA residues 1892 and 2433-2434, respectively, in the ribosomal E site. These results establish a set of functional interactions between P-site tRNA and 23S rRNA that are essential for translocation.
authors.affiliation: Department of Chemistry and Biochemistry, University of California at San Diego, La Jolla, CA 92093-0314, USA.
authors.forename: J S
authors.initials: JS
authors.lastname: Feinberg
authors.forename: S
authors.initials: S
authors.lastname: Joseph
mesh_terms: D001483:Base Sequence; D001665:Binding Sites; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D007700:Kinetics; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D009843:Oligoribonucleotides / Q000138:chemical synthesis / Q000737:chemistry / Q000378:metabolism; D010441:Peptide Chain Elongation, Translational; D012329:RNA, Bacterial / Q000737:chemistry / Q000378:metabolism; D012338:RNA, Ribosomal, 23S / Q000737:chemistry* / Q000378:metabolism*; D012358:RNA, Transfer, Met / Q000737:chemistry* / Q000378:metabolism*; D012270:Ribosomes / Q000378:metabolism*; D014158:Transcription, Genetic
chemical_list: D009843:Oligoribonucleotides; D012329:RNA, Bacterial; D012338:RNA, Ribosomal, 23S; D012358:RNA, Transfer, Met