One protein from two open reading frames: mechanism of a 50 nt translational bypass.

Abstract

Translating ribosomes bypass a 50 nt coding gap in order to fuse the information found in the two open reading frames (ORFs) of bacteriophage T4 gene 60. This study investigates the underlying mechanism by focusing on the competition between initiation of bypassing and termination at the end of the first ORF. While nearly all ribosomes initiate bypassing, no more than 50% resume translation in the second ORF. Two previously described cis-acting stimulatory signals are critical for favoring initiation of bypassing over termination. Genetic analysis of these signals supports a working model in which the first (a stem-loop structure at the junction between the first ORF and the coding gap) interferes with decoding in the A-site, and the second (a stretch of amino acids in the nascent peptide encoded by the first ORF) destabilizes peptidyl-tRNA-mRNA pairing.

• Authors: A J Herr, R F Gesteland, J F Atkins
• Journal: The EMBO journal (EMBO J) Vol. 19 Issue 11 Pg. 2671-80 (Jun 01 2000) ISSN: 0261-4189 [Print] England
• PMID: 10835364 (Publication Type: Journal Article, Research Support, U.S. Gov't, Non-P.H.S., Research Support, U.S. Gov't, P.H.S.)

Chemical References

• Codon
• Protein Sorting Signals
• RNA, Transfer, Gly

Topics

• Amino Acid Sequence
• Bacteriophage T4 (genetics, metabolism)
• Base Sequence
• Codon (genetics)
• Molecular Sequence Data
• Open Reading Frames
• Protein Biosynthesis
• Protein Sorting Signals (genetics, metabolism)
• RNA, Transfer, Gly (genetics)
• Ribosomes (physiology)