skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Volume-conserving trans-cis isomerization pathways in photoactive yellow protein visualized by picosecond X-ray crystallography

Abstract

Trans-to-cis isomerization, the key reaction in photoactive proteins, usually cannot occur through the standard one-bond-flip mechanism. Owing to spatial constraints imposed by a protein environment, isomerization probably proceeds through a volume-conserving mechanism in which highly choreographed atomic motions are expected, the details of which have not yet been observed directly. Here we employ time-resolved X-ray crystallography to visualize structurally the isomerization of the p-coumaric acid chromophore in photoactive yellow protein with a time resolution of 100 ps and a spatial resolution of 1.6 Å. The structure of the earliest intermediate (I T) resembles a highly strained transition state in which the torsion angle is located halfway between the trans- and cis-isomers. The reaction trajectory of IT bifurcates into two structurally distinct cis intermediates via hula-twist and bicycle-pedal pathways. The bifurcating reaction pathways can be controlled by weakening the hydrogen bond between the chromophore and an adjacent residue through E46Q mutation, which switches off the bicycle-pedal pathway.

Authors:
; ; ; ; ; ;  [1];  [2];  [2]
  1. KAIST-D
  2. (
Publication Date:
Research Org.:
Argonne National Lab. (ANL), Argonne, IL (United States). Advanced Photon Source (APS)
Sponsoring Org.:
FOREIGNNSFNIH
OSTI Identifier:
1063643
Resource Type:
Journal Article
Journal Name:
Nature Chemistry
Additional Journal Information:
Journal Volume: 5; Journal ID: ISSN 1755-4330
Country of Publication:
United States
Language:
ENGLISH

Citation Formats

Jung, Yang Ouk, Lee, Jae Hyuk, Kim, Joonghan, Schmidt, Marius, Moffat, Keith, Šrajer, Vukica, Ihee, Hyotcherl, UW), and UC). Volume-conserving trans-cis isomerization pathways in photoactive yellow protein visualized by picosecond X-ray crystallography. United States: N. p., 2013. Web. doi:10.1038/nchem.1565.
Jung, Yang Ouk, Lee, Jae Hyuk, Kim, Joonghan, Schmidt, Marius, Moffat, Keith, Šrajer, Vukica, Ihee, Hyotcherl, UW), & UC). Volume-conserving trans-cis isomerization pathways in photoactive yellow protein visualized by picosecond X-ray crystallography. United States. doi:10.1038/nchem.1565.
Jung, Yang Ouk, Lee, Jae Hyuk, Kim, Joonghan, Schmidt, Marius, Moffat, Keith, Šrajer, Vukica, Ihee, Hyotcherl, UW), and UC). Sun . "Volume-conserving trans-cis isomerization pathways in photoactive yellow protein visualized by picosecond X-ray crystallography". United States. doi:10.1038/nchem.1565.
@article{osti_1063643,
title = {Volume-conserving trans-cis isomerization pathways in photoactive yellow protein visualized by picosecond X-ray crystallography},
author = {Jung, Yang Ouk and Lee, Jae Hyuk and Kim, Joonghan and Schmidt, Marius and Moffat, Keith and Šrajer, Vukica and Ihee, Hyotcherl and UW) and UC)},
abstractNote = {Trans-to-cis isomerization, the key reaction in photoactive proteins, usually cannot occur through the standard one-bond-flip mechanism. Owing to spatial constraints imposed by a protein environment, isomerization probably proceeds through a volume-conserving mechanism in which highly choreographed atomic motions are expected, the details of which have not yet been observed directly. Here we employ time-resolved X-ray crystallography to visualize structurally the isomerization of the p-coumaric acid chromophore in photoactive yellow protein with a time resolution of 100 ps and a spatial resolution of 1.6 Å. The structure of the earliest intermediate (IT) resembles a highly strained transition state in which the torsion angle is located halfway between the trans- and cis-isomers. The reaction trajectory of IT bifurcates into two structurally distinct cis intermediates via hula-twist and bicycle-pedal pathways. The bifurcating reaction pathways can be controlled by weakening the hydrogen bond between the chromophore and an adjacent residue through E46Q mutation, which switches off the bicycle-pedal pathway.},
doi = {10.1038/nchem.1565},
journal = {Nature Chemistry},
issn = {1755-4330},
number = ,
volume = 5,
place = {United States},
year = {2013},
month = {2}
}