RT Journal Article
SR Electronic
T1 Nascent polypeptide within the exit tunnel ensures continuous translation elongation by stabilizing the translating ribosome
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 2021.02.02.429294
DO 10.1101/2021.02.02.429294
A1 Chadani, Yuhei
A1 Sugata, Nobuyuki
A1 Niwa, Tatsuya
A1 Ito, Yosuke
A1 Iwasaki, Shintaro
A1 Taguchi, Hideki
YR 2021
UL http://biorxiv.org/content/early/2021/02/02/2021.02.02.429294.abstract
AB Continuous translation elongation, irrespective of amino acid sequences, is a prerequisite for living organisms to produce their proteomes. However, the risk of elongation abortion is concealed within nascent polypeptide products. Negatively charged sequences with occasional intermittent prolines, termed intrinsic ribosome destabilization (IRD) sequences, destabilizes the translating ribosomal complex. Thus, some nascent chain sequences lead to premature translation cessation. Here, we show that the risk of IRD is maximal at the N-terminal regions of proteins encoded by dozens of Escherichia coli genes. In contrast, most potential IRD sequences in the middle of open reading frames remain cryptic. We found two elements in nascent chains that counteract IRD: the nascent polypeptide itself that spans the exit tunnel and its bulky amino acid residues that occupy the tunnel entrance region. Thus, nascent polypeptide products have a built-in ability to ensure elongation continuity by serving as a bridge and thus by protecting the large and small ribosomal subunits from dissociation.Competing Interest StatementThe authors have declared no competing interest.