A homing endonuclease and the 50-nt ribosomal bypass sequence of phage T4 constitute a mobile DNA cassette.

ABSTRACT: Since its initial description more than two decades ago, the ribosome bypass (or "hop") sequence of phage T4 stands out as a uniquely extreme example of programmed translational frameshifting. The gene for a DNA topoisomerase subunit of T4 has been split by a 1-kb insertion into two genes that retain topoisomerase function. A second 50-nt insertion, beginning with an in-phase stop codon, is inserted near the start of the newly created downstream gene 60. Instead of terminating at this stop codon, approximately half of the ribosomes skip 50 nucleotides and continue translation in a new reading frame. However, no functions, regulatory or otherwise, have been imputed for the truncated peptide that results from termination at codon 46 or for the bypass sequence itself. Moreover, how this unusu

SUBMITTER: Bonocora RP 

PROVIDER: S-EPMC3182709 | biostudies-literature | 2011 Sep

REPOSITORIES: biostudies-literature