COUPLING OF OPEN READING FRAMES BY TRANSLATIONAL BYPASSING

• Published in: Annual review of biochemistry Vol. 69; no. 1; pp. 343 - 372
• Main Authors: Herr, Alan J, Atkins, John F, Gesteland, Raymond F
• Format: Journal Article
• Language: English
• Published: Palo Alto, CA 94303-0139 Annual Reviews 01.01.2000; 4139 El Camino Way, P.O. Box 10139 Annual Reviews, Inc; USA
• Subjects: Amino Acid Sequence; Base Sequence; bypassing; gene; gene 60; Genes, Bacterial; hopping; Models, Biological; Models, Molecular; Molecular Sequence Data; Open Reading Frames; Peptide Chain Termination, Translational; peptidyl transferase; Phage T4; Protein Biosynthesis; Protein Sorting Signals - genetics; Ribosomal Proteins - genetics; Ribosomal Proteins - metabolism; RNA, Bacterial - genetics; RNA, Bacterial - metabolism; RNA, Ribosomal, 16S - genetics; RNA, Ribosomal, 16S - metabolism; RNA, Ribosomal, 23S - genetics; RNA, Ribosomal, 23S - metabolism; RNA, Transfer, Amino Acyl - genetics; RNA, Transfer, Amino Acyl - metabolism; translation
• ISSN: 0066-4154; 1545-4509
• DOI: 10.1146/annurev.biochem.69.1.343

Translational bypassing joins the information found within two disparate open reading frames into a single polypeptide chain. The underlying mechanism centers on the decoding properties of peptidyl-transfer RNA (tRNA) and involves three stages: take-off, scanning, and landing. In take-off, the peptidyl-tRNA/messenger RNA (mRNA) complex in the P site of the ribosome dissociates, and the mRNA begins to move through the ribosome. In scanning, the peptidyl-tRNA probes the mRNA sliding through the decoding center. In landing, the peptidyl-tRNA re-pairs with a codon with which it can form a stable interaction. Although few examples of genes are known that rely on translational bypassing to couple open reading frames, ribosomes appear to have an innate capacity for bypassing. This suggests that the strategy of translational bypassing may be more common than presently appreciated. The best characterized example of this phenomenon is T4 gene 60 , in which a complex set of signals stimulates bypassing of 50 nucleotides between the two open reading frames. In this review, we focus on the bypassing mechanism of gene 60 in terms of take-off, scanning, and landing.