The solution structure of a transient photoreceptor intermediate: Delta25 photoactive yellow protein.

TitleThe solution structure of a transient photoreceptor intermediate: Delta25 photoactive yellow protein.
Publication TypeJournal Article
Year of Publication2005
AuthorsBernard, C., K. Houben, N. M. Derix, D. Marks, M. A. van der Horst, K. J. Hellingwerf, R. Boelens, R. Kaptein, and N. A. J. van Nuland
JournalStructure
Volume13
Issue7
Pagination953-62
Date Published2005 Jul
ISSN0969-2126
KeywordsBacterial Proteins, Crystallography, X-Ray, Halorhodospira halophila, Light, Magnetic Resonance Spectroscopy, Models, Chemical, Models, Molecular, Models, Statistical, Photoreceptors, Microbial, Protein Conformation, Protein Folding, Protein Structure, Tertiary, Protons, Signal Transduction, X-Rays
Abstract

The N-terminally truncated variant of photoactive yellow protein (Delta25-PYP) undergoes a very similar photocycle as the corresponding wild-type protein (WT-PYP), although the lifetime of its light-illuminated (pB) state is much longer. This has allowed determination of the structure of both its dark- (pG) as well as its pB-state in solution by nuclear magnetic resonance (NMR) spectroscopy. The pG structure shows a well-defined fold, similar to WT-PYP and the X-ray structure of the pG state of Delta25-PYP. In the long-lived photocycle intermediate pB, the central beta sheet is still intact, as well as a small part of one alpha helix. The remainder of pB is unfolded and highly flexible, as evidenced by results from proton-deuterium exchange and NMR relaxation studies. Thus, the partially unfolded nature of the presumed signaling state of PYP in solution, as suggested previously, has now been structurally demonstrated.

DOI10.1016/j.str.2005.04.017
Alternate JournalStructure
PubMed ID16004868