Structures of the bacterial ribosome in classical and hybrid states of tRNA binding.
Publication Type:Journal Article
Source:Science, Volume 332, Issue 6032, p.981-4 (2011)
Keywords:Anticodon, Crystallography, X-Ray, Escherichia coli, Escherichia coli Proteins, Models, Molecular, Nucleic Acid Conformation, Protein Biosynthesis, Ribosomal Proteins, Ribosome Subunits, Large, Bacterial, Ribosome Subunits, Small, Bacterial, RNA, Bacterial, RNA, Messenger, RNA, Ribosomal, 16S, RNA, Ribosomal, 23S, RNA, Transfer, Amino Acyl, RNA, Transfer, Phe
<p>During protein synthesis, the ribosome controls the movement of tRNA and mRNA by means of large-scale structural rearrangements. We describe structures of the intact bacterial ribosome from Escherichia coli that reveal how the ribosome binds tRNA in two functionally distinct states, determined to a resolution of ~3.2 angstroms by means of x-ray crystallography. One state positions tRNA in the peptidyl-tRNA binding site. The second, a fully rotated state, is stabilized by ribosome recycling factor and binds tRNA in a highly bent conformation in a hybrid peptidyl/exit site. The structures help to explain how the ratchet-like motion of the two ribosomal subunits contributes to the mechanisms of translocation, termination, and ribosome recycling.</p>