title: Structural basis of the ribosomal machinery for peptide bond formation, translocation, and nascent chain progression.
abstract: Crystal structures of tRNA mimics complexed with the large ribosomal subunit of Deinococcus radiodurans indicate that remote interactions determine the precise orientation of tRNA in the peptidyl-transferase center (PTC). The PTC tolerates various orientations of puromycin derivatives and its flexibility allows the conformational rearrangements required for peptide-bond formation. Sparsomycin binds to A2602 and alters the PTC conformation. H69, the intersubunit-bridge connecting the PTC and decoding site, may also participate in tRNA placement and translocation. A spiral rotation of the 3' end of the A-site tRNA around a 2-fold axis of symmetry identified within the PTC suggests a unified ribosomal machinery for peptide-bond formation, A-to-P-site translocation, and entrance of nascent proteins into the exit tunnel. Similar 2-fold related regions, detected in all known structures of large ribosomal subunits, indicate the universality of this mechanism.
authors.affiliation: Department of Structural Biology, Weizmann Institute, 76100 Rehovot, Israel.
authors.forename: Anat
authors.initials: A
authors.lastname: Bashan
authors.forename: Ilana
authors.initials: I
authors.lastname: Agmon
authors.forename: Raz
authors.initials: R
authors.lastname: Zarivach
authors.forename: Frank
authors.initials: F
authors.lastname: Schluenzen
authors.forename: Joerg
authors.initials: J
authors.lastname: Harms
authors.forename: Rita
authors.initials: R
authors.lastname: Berisio
authors.forename: Heike
authors.initials: H
authors.lastname: Bartels
authors.forename: Francois
authors.initials: F
authors.lastname: Franceschi
authors.forename: Tamar
authors.initials: T
authors.lastname: Auerbach
authors.forename: Harly A S
authors.initials: HA
authors.lastname: Hansen
authors.forename: Elizaveta
authors.initials: E
authors.lastname: Kossoy
authors.forename: Maggie
authors.initials: M
authors.lastname: Kessler
authors.forename: Ada
authors.initials: A
authors.lastname: Yonath
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D020134:Catalytic Domain; D018360:Crystallography, X-Ray; D034301:Deinococcus / Q000235:genetics*; D008958:Models, Molecular; D015394:Molecular Structure; D009690:Nucleic Acid Conformation; D014176:Protein Biosynthesis; D011487:Protein Conformation; D011500:Protein Synthesis Inhibitors / Q000737:chemistry / Q000378:metabolism; D011691:Puromycin / Q000737:chemistry / Q000378:metabolism; D012346:RNA, Transfer, Amino Acyl / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D012269:Ribosomal Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D013033:Sparsomycin / Q000737:chemistry / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D011500:Protein Synthesis Inhibitors; D012346:RNA, Transfer, Amino Acyl; D012269:Ribosomal Proteins; D011691:Puromycin; D013033:Sparsomycin