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Medicine and Health Sciences Commons

Open Access. Powered by Scholars. Published by Universities.®

Medical Biochemistry

Thomas Jefferson University

2021

Transfer

Articles 1 - 2 of 2

Full-Text Articles in Medicine and Health Sciences

Structural Basis For +1 Ribosomal Frameshifting During Ef-G-Catalyzed Translocation., Gabriel Demo, Howard Gamper, Anna B. Loveland, Isao Masuda, Christine E. Carbone, Egor Svidritskiy, Ya-Ming Hou, Andrei A. Korostelev Jul 2021

Structural Basis For +1 Ribosomal Frameshifting During Ef-G-Catalyzed Translocation., Gabriel Demo, Howard Gamper, Anna B. Loveland, Isao Masuda, Christine E. Carbone, Egor Svidritskiy, Ya-Ming Hou, Andrei A. Korostelev

Department of Biochemistry and Molecular Biology Faculty Papers

Frameshifting of mRNA during translation provides a strategy to expand the coding repertoire of cells and viruses. How and where in the elongation cycle +1-frameshifting occurs remains poorly understood. We describe seven ~3.5-Å-resolution cryo-EM structures of 70S ribosome complexes, allowing visualization of elongation and translocation by the GTPase elongation factor G (EF-G). Four structures with a + 1-frameshifting-prone mRNA reveal that frameshifting takes place during translocation of tRNA and mRNA. Prior to EF-G binding, the pre-translocation complex features an in-frame tRNA-mRNA pairing in the A site. In the partially translocated structure with EF-G•GDPCP, the tRNA shifts to the +1-frame near …


Insights Into Genome Recoding From The Mechanism Of A Classic +1-Frameshifting Trna., Howard Gamper, Haixing Li, Isao Masuda, D. Miklos Robkis, Thomas Christian, Adam B. Conn, Gregor Blaha, E. James Petersson, Ruben L. Gonzalez, Ya-Ming Hou Jan 2021

Insights Into Genome Recoding From The Mechanism Of A Classic +1-Frameshifting Trna., Howard Gamper, Haixing Li, Isao Masuda, D. Miklos Robkis, Thomas Christian, Adam B. Conn, Gregor Blaha, E. James Petersson, Ruben L. Gonzalez, Ya-Ming Hou

Department of Biochemistry and Molecular Biology Faculty Papers

While genome recoding using quadruplet codons to incorporate non-proteinogenic amino acids is attractive for biotechnology and bioengineering purposes, the mechanism through which such codons are translated is poorly understood. Here we investigate translation of quadruplet codons by a +1-frameshifting tRNA, SufB2, that contains an extra nucleotide in its anticodon loop. Natural post-transcriptional modification of SufB2 in cells prevents it from frameshifting using a quadruplet-pairing mechanism such that it preferentially employs a triplet-slippage mechanism. We show that SufB2 uses triplet anticodon-codon pairing in the 0-frame to initially decode the quadruplet codon, but subsequently shifts to the +1-frame during tRNA-mRNA translocation. SufB2 …