Pulling the ribosome out of frame by +1 at a programmed frameshift site by cognate binding of aminoacyl-tRNA.
Programmed translational frameshifts efficiently alter a translational reading frame by shifting the reading frame during translation. A +1 frameshift has two simultaneous requirements: a translational pause which occurs when either an inefficiently recognized sense or termination codon occupies the A site, and the presence of a special peptidyl-tRNA occupying the P site during the pause. The special nature of the peptidyl-tRNA reflects its ability to slip +1 on the mRNA or to facilitate binding of an incoming aminoacyl-tRNA out of frame in the A site. This second mechanism suggested that in some cases the first +1 frame tRNA could have an active role in frameshifting. We found that overproducing this tRNA can drive frameshifting, surprisingly regardless of whether frameshifting occurs by peptidyl-tRNA slippage or out-of-frame binding of aminoacyl-tRNA. This finding suggests that in both cases, the shift in reading frame occurs coincident with formation of a cognate codon-anticodon interaction in the shifted frame.
Pande
S
S
Department of Biological Sciences, University of Maryland, Baltimore 21228.
Vimaladithan
A
A
Zhao
H
H
Farabaugh
P J
PJ
D000926:Anticodon; D001483:Base Sequence; D003062:Codon; D008969:Molecular Sequence Data; D010455:Peptides / Q000378:metabolism; D014176:Protein Biosynthesis; D012331:RNA, Fungal / Q000235:genetics; D012333:RNA, Messenger / Q000378:metabolism*; D012346:RNA, Transfer, Amino Acyl / Q000378:metabolism*; D012270:Ribosomes / Q000378:metabolism*; D012441:Saccharomyces cerevisiae
D000926:Anticodon; D003062:Codon; D010455:Peptides; D012331:RNA, Fungal; D012333:RNA, Messenger; D012346:RNA, Transfer, Amino Acyl