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Spectroscopy and a high-resolution crystal structure of Tyr263 mutants of cyanobacterial phytochrome Cph1.
- Source :
-
Journal of molecular biology [J Mol Biol] 2011 Oct 14; Vol. 413 (1), pp. 115-27. Date of Electronic Publication: 2011 Aug 23. - Publication Year :
- 2011
-
Abstract
- Phytochromes are biliprotein photoreceptors that can be photoswitched between red-light-absorbing state (Pr) and far-red-light-absorbing state (Pfr). Although three-dimensional structures of both states have been reported, the photoconversion and intramolecular signaling mechanisms are still unclear. Here, we report UV-Vis absorbance, fluorescence and CD spectroscopy along with various photochemical parameters of the wild type and Y263F, Y263H and Y263S mutants of the Cph1 photosensory module, as well as a 2.0-Å-resolution crystal structure of the Y263F mutant in its Pr ground state. Although Y263 is conserved, we show that the aromatic character but not the hydroxyl group of Y263 is important for Pfr formation. The crystal structure of the Y263F mutant (Protein Data Bank ID: 3ZQ5) reaffirms the ZZZssa chromophore configuration and provides a detailed picture of its binding pocket, particularly conformational heterogeneity around the chromophore. Comparison with other phytochrome structures reveals differences in the relative position of the PHY (phytochrome specific) domain and the interaction of the tongue with the extreme N-terminus. Our data support the notion that native phytochromes in their Pr state are structurally heterogeneous.<br /> (Copyright © 2011 Elsevier Ltd. All rights reserved.)
- Subjects :
- Bacterial Proteins genetics
Bacterial Proteins isolation & purification
Binding Sites
Crystallography, X-Ray
Cyanobacteria chemistry
Models, Molecular
Mutant Proteins chemistry
Mutant Proteins genetics
Mutant Proteins isolation & purification
Photoreceptors, Microbial
Phytochrome genetics
Phytochrome isolation & purification
Protein Conformation
Protein Kinases genetics
Protein Kinases isolation & purification
Spectrum Analysis
Amino Acid Substitution genetics
Bacterial Proteins chemistry
Phytochrome chemistry
Protein Kinases chemistry
Subjects
Details
- Language :
- English
- ISSN :
- 1089-8638
- Volume :
- 413
- Issue :
- 1
- Database :
- MEDLINE
- Journal :
- Journal of molecular biology
- Publication Type :
- Academic Journal
- Accession number :
- 21888915
- Full Text :
- https://doi.org/10.1016/j.jmb.2011.08.023