title: The 30S ribosomal P site: a function of 16S rRNA.
abstract: The 30S ribosomal P site serves several functions in translation. It must specifically bind initiator tRNA during formation of the 30S initiation complex; bind the anticodon stem-loop of peptidyl-tRNA during the elongation phase; and help to maintain the translational reading frame when the A site is unoccupied. Early experiments provided evidence that 16S rRNA was an important component of the 30S P site. Footprinting and crosslinking studies later implicated specific nucleotides in interactions with tRNA. The crystal structures of the 30S subunit and 70S ribosome-tRNA complexes confirmed the interactions between 16S rRNA and tRNA, but also revealed contacts between tRNA and the C-terminal tails of proteins S9 and S13. Deletion of these tails now shows that the 16S rRNA contacts alone are sufficient to support protein synthesis in living cells.
authors.affiliation: Department of Molecular, Cell and Developmental Biology, Center for Molecular Biology of RNA, University of California at Santa Cruz, CA 95064, USA. noller@biology.ucsc.edu
authors.forename: Harry F
authors.initials: HF
authors.lastname: Noller
authors.forename: Lee
authors.initials: L
authors.lastname: Hoang
authors.forename: Kurt
authors.initials: K
authors.lastname: Fredrick
mesh_terms: D020134:Catalytic Domain; D003461:Crystallography; D009690:Nucleic Acid Conformation; D017433:Protein Structure, Secondary; D012336:RNA, Ribosomal, 16S / Q000737:chemistry* / Q000378:metabolism / Q000502:physiology*; D012343:RNA, Transfer / Q000737:chemistry / Q000378:metabolism; D012269:Ribosomal Proteins / Q000737:chemistry / Q000502:physiology; D012270:Ribosomes / Q000737:chemistry / Q000378:metabolism / Q000502:physiology*
chemical_list: D012336:RNA, Ribosomal, 16S; D012269:Ribosomal Proteins; D012343:RNA, Transfer