eprintid: 10076232 rev_number: 19 eprint_status: archive userid: 608 dir: disk0/10/07/62/32 datestamp: 2019-06-19 14:06:19 lastmod: 2021-10-04 01:02:09 status_changed: 2019-06-19 14:06:19 type: article metadata_visibility: show creators_name: Peran, I creators_name: Holehouse, AS creators_name: Carrico, IS creators_name: Pappu, RV creators_name: Bilsel, O creators_name: Raleigh, DP title: Unfolded states under folding conditions accommodate sequence-specific conformational preferences with random coil-like dimensions ispublished: pub divisions: UCL divisions: B02 divisions: C08 divisions: D09 divisions: G03 keywords: FRET, compaction transition, protein folding, unfolded state note: © 2019 the Author(s). Published by PNAS. This open access article is distributed under Creative Commons Attribution-NonCommercial-NoDerivatives License 4.0 (https://creativecommons.org/licenses/by-nc-nd/4.0/). abstract: Proteins are marginally stable molecules that fluctuate between folded and unfolded states. Here, we provide a high-resolution description of unfolded states under refolding conditions for the N-terminal domain of the L9 protein (NTL9). We use a combination of time-resolved Förster resonance energy transfer (FRET) based on multiple pairs of minimally perturbing labels, time-resolved small-angle X-ray scattering (SAXS), all-atom simulations, and polymer theory. Upon dilution from high denaturant, the unfolded state undergoes rapid contraction. Although this contraction occurs before the folding transition, the unfolded state remains considerably more expanded than the folded state and accommodates a range of local and nonlocal contacts, including secondary structures and native and nonnative interactions. Paradoxically, despite discernible sequence-specific conformational preferences, the ensemble-averaged properties of unfolded states are consistent with those of canonical random coils, namely polymers in indifferent (theta) solvents. These findings are concordant with theoretical predictions based on coarse-grained models and inferences drawn from single-molecule experiments regarding the sequence-specific scaling behavior of unfolded proteins under folding conditions. date: 2019-06-18 date_type: published official_url: https://doi.org/10.1073/pnas.1818206116 oa_status: green full_text_type: pub language: eng primo: open primo_central: open_green article_type_text: Journal Article verified: verified_manual elements_id: 1664446 doi: 10.1073/pnas.1818206116 pii: 1818206116 language_elements: English lyricists_name: Raleigh, Daniel lyricists_id: DRALE20 actors_name: Flynn, Bernadette actors_id: BFFLY94 actors_role: owner full_text_status: public publication: Proceedings of the National Academy of Sciences of the United States of America volume: 116 number: 25 pagerange: 12301-12310 event_location: United States issn: 1091-6490 citation: Peran, I; Holehouse, AS; Carrico, IS; Pappu, RV; Bilsel, O; Raleigh, DP; (2019) Unfolded states under folding conditions accommodate sequence-specific conformational preferences with random coil-like dimensions. Proceedings of the National Academy of Sciences of the United States of America , 116 (25) pp. 12301-12310. 10.1073/pnas.1818206116 <https://doi.org/10.1073/pnas.1818206116>. Green open access document_url: https://discovery-pp.ucl.ac.uk/id/eprint/10076232/8/Raleigh_Unfolded%20states%20under%20folding%20conditions%20accommodate%20sequence-specific%20conformational%20preferences%20with%20random%20coil-like%20dimensions_VoR.pdf