Influence of the PHY domain on the ms-photoconversion dynamics of a knotless phytochrome.

Autor: Fischer T; Institute of Physical and Theoretical Chemistry, Goethe University Frankfurt Am Main, Max-von-Laue-Straße 7, 60438, Frankfurt, Germany., Köhler L; Institute for Analytical Chemistry, University of Leipzig, Linnéstraße 3, 04103, Leipzig, Germany., Ott T; Institute of Physical and Theoretical Chemistry, Goethe University Frankfurt Am Main, Max-von-Laue-Straße 7, 60438, Frankfurt, Germany., Song C; Institute for Analytical Chemistry, University of Leipzig, Linnéstraße 3, 04103, Leipzig, Germany., Wachtveitl J; Institute of Physical and Theoretical Chemistry, Goethe University Frankfurt Am Main, Max-von-Laue-Straße 7, 60438, Frankfurt, Germany. wveitl@theochem.uni-frankfurt.de., Slavov C; Institute of Physical and Theoretical Chemistry, Goethe University Frankfurt Am Main, Max-von-Laue-Straße 7, 60438, Frankfurt, Germany. chslavov@theochem.uni-frankfurt.de.
Jazyk: angličtina
Zdroj: Photochemical & photobiological sciences : Official journal of the European Photochemistry Association and the European Society for Photobiology [Photochem Photobiol Sci] 2022 Sep; Vol. 21 (9), pp. 1627-1636. Date of Electronic Publication: 2022 Jun 10.
DOI: 10.1007/s43630-022-00245-9
Abstrakt: The ability of some knotless phytochromes to photoconvert without the PHY domain allows evaluation of the distinct effect of the PHY domain on their photodynamics. Here, we compare the ms dynamics of the single GAF domain (g1) and the GAF-PHY (g1g2) construct of the knotless phytochrome All2699 from cyanobacterium Nostoc punctiforme. While the spectral signatures and occurrence of the intermediates are mostly unchanged by the domain composition, the presence of the PHY domain slows down the early forward and reverse dynamics involving chromophore and protein binding pocket relaxation. We assign this effect to a more restricted binding pocket imprinted by the PHY domain. The photoproduct formation is also slowed down by the presence of the PHY domain but to a lesser extent than the early dynamics. This indicates a rate limiting step within the GAF and not the PHY domain. We further identify a pH dependence of the biphasic photoproduct formation hinting towards a pKa dependent tuning mechanism. Our findings add to the understanding of the role of the individual domains in the photocycle dynamics and provide a basis for engineering of phytochromes towards biotechnological applications.
(© 2022. The Author(s).)
Databáze: MEDLINE
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