5np6
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70S structure prior to bypassing70S structure prior to bypassing
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Structural highlights
FunctionTOPS_BPT4 Control of topological states of DNA by transient breakage and subsequent rejoining of DNA strands. T4 topoisomerase makes double-strand breaks. Publication Abstract from PubMedBypassing is a recoding event that leads to the translation of two distal open reading frames into a single polypeptide chain. We present the structure of a translating ribosome stalled at the bypassing take-off site of gene 60 of bacteriophage T4. The nascent peptide in the exit tunnel anchors the P-site peptidyl-tRNAGly to the ribosome and locks an inactive conformation of the peptidyl transferase center (PTC). The mRNA forms a short dynamic hairpin in the decoding site. The ribosomal subunits adopt a rolling conformation in which the rotation of the small subunit around its long axis causes the opening of the A-site region. Together, PTC conformation and mRNA structure safeguard against premature termination and read-through of the stop codon and reconfigure the ribosome to a state poised for take-off and sliding along the noncoding mRNA gap. Ribosome rearrangements at the onset of translational bypassing.,Agirrezabala X, Samatova E, Klimova M, Zamora M, Gil-Carton D, Rodnina MV, Valle M Sci Adv. 2017 Jun 7;3(6):e1700147. doi: 10.1126/sciadv.1700147. eCollection 2017 , Jun. PMID:28630923[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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