3i9b

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3i9b, resolution 3.50Å ()
Ligands: ,
Related: 3i8h, 3i8i, 3i8g, 3i8f, 3i9c, 3i9d, 3i9e


Resources: FirstGlance, OCA, PDBsum, RCSB
Coordinates: save as pdb, mmCIF, xml



Contents

Initiation complex of 70S ribosome with two tRNAs and mRNA. This entry 3I9B contains 30S ribosomal subunit of molecule B. The 50S ribosomal subunit can be found in PDB entry 3I9C. Molecule A in the same asymmetric unit is deposited as 3I9D (30S) and 3I9E (50S)

Publication Abstract from PubMed

One key question in protein biosynthesis is how the ribosome couples mRNA and tRNA movements to prevent disruption of weak codon-anticodon interactions and loss of the translational reading frame during translocation. Here we report the complete path of mRNA on the 70S ribosome at the atomic level (3.1-A resolution), and we show that one of the conformational rearrangements that occurs upon transition from initiation to elongation is a narrowing of the downstream mRNA tunnel. This rearrangement triggers formation of a network of interactions between the mRNA downstream of the A-site codon and the elongating ribosome. Our data elucidate the mechanism by which hypermodified nucleoside 2-methylthio-N6 isopentenyl adenosine at position 37 (ms(2)i(6)A37) in tRNA(Phe)(GAA) stabilizes mRNA-tRNA interactions in all three tRNA binding sites. Another network of contacts is formed between this tRNA modification and ribosomal elements surrounding the mRNA E/P kink, resulting in the anchoring of P-site tRNA. These data allow rationalization of how modification deficiencies of ms(2)i(6)A37 in tRNAs may lead to shifts of the translational reading frame.

Structural aspects of messenger RNA reading frame maintenance by the ribosome., Jenner LB, Demeshkina N, Yusupova G, Yusupov M, Nat Struct Mol Biol. 2010 May;17(5):555-60. Epub 2010 Apr 18. PMID:20400952

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

About this Structure

3i9b is a 24 chain structure with sequence from Escherichia coli and Thermus thermophilus. Full crystallographic information is available from OCA.

See Also

Reference

  • Jenner LB, Demeshkina N, Yusupova G, Yusupov M. Structural aspects of messenger RNA reading frame maintenance by the ribosome. Nat Struct Mol Biol. 2010 May;17(5):555-60. Epub 2010 Apr 18. PMID:20400952 doi:10.1038/nsmb.1790
  • Jenner L, Demeshkina N, Yusupova G, Yusupov M. Structural rearrangements of the ribosome at the tRNA proofreading step. Nat Struct Mol Biol. 2010 Sep;17(9):1072-8. Epub 2010 Aug 8. PMID:20694005 doi:10.1038/nsmb.1880

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