The ribosome modulates folding inside the ribosomal exit tunnel
Florian Wruck (Kavli institute of nanoscience Delft, TU Delft - BN/Sander Tans Lab, AMOLF Institute for Atomic and Molecular Physics)
Pengfei Tian (Novozymes A/S)
Renuka Kudva (Stockholm University)
Robert B. Best (NIH)
Gunnar von Heijne (Stockholm University)
Sander J. Tans (TU Delft - BN/Sander Tans Lab, AMOLF Institute for Atomic and Molecular Physics, Kavli institute of nanoscience Delft)
Alexandros Katranidis (Forschungszentrum Jülich)
More Info
expand_more
Other than for strictly personal use, it is not permitted to download, forward or distribute the text or part of it, without the consent of the author(s) and/or copyright holder(s), unless the work is under an open content license such as Creative Commons.
Abstract
Proteins commonly fold co-translationally at the ribosome, while the nascent chain emerges from the ribosomal exit tunnel. Protein domains that are sufficiently small can even fold while still located inside the tunnel. However, the effect of the tunnel on the folding dynamics of these domains is not well understood. Here, we combine optical tweezers with single-molecule FRET and molecular dynamics simulations to investigate folding of the small zinc-finger domain ADR1a inside and at the vestibule of the ribosomal tunnel. The tunnel is found to accelerate folding and stabilize the folded state, reminiscent of the effects of chaperonins. However, a simple mechanism involving stabilization by confinement does not explain the results. Instead, it appears that electrostatic interactions between the protein and ribosome contribute to the observed folding acceleration and stabilization of ADR1a.
help_outline