RT Journal Article
SR Electronic
T1 Visualising nascent chain dynamics at the ribosome exit tunnel by cryo-electron microscopy
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 722611
DO 10.1101/722611
A1 Javed, Abid
A1 Wlodarski, Tomasz
A1 Cassaignau, Anaïs. M.E.
A1 Cabrita, Lisa D.
A1 Christodoulou, John
A1 Orlova, Elena V.
YR 2019
UL http://biorxiv.org/content/early/2019/12/16/722611.abstract
AB Ribosomes maintain a healthy cellular proteome by synthesising proteins. The nascent chain (NC), emerges into the cellular milieu via the ribosomal exit tunnel, which is an active component that regulates the NC passage. How the NC dynamics at the exit tunnel affect NC folding remains to be an important question, the answer on which has strong implications to medicine. Here, we report high-resolution cryo-EM maps of ribosome nascent-chain complexes (RNCs) displaying distinct steps during biosynthesis. These RNC structures reveal a range of pathways adopted by the NC. The most pronounced diversity in the NC trajectories were found in the vestibule region. Rearrangements of several ribosomal components further suggest that these elements may actively monitor the emerging NC during translation. The ribosome-NC contacts within the vestibule define these NC pathways and modulate position of a folded immunoglobulin domain outside the ribosome.