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Transient IR spectroscopy identifies key interactions and unravels new intermediates in the photocycle of a bacterial phytochrome

Kübel, Joachim ; Chenchiliyan, Manoop LU ; Ooi, Saik Ann ; Gustavsson, Emil ; Isaksson, Linnéa ; Kuznetsova, Valentyna ; Ihalainen, Janne A. ; Westenhoff, Sebastian LU and Maj, Michał (2020) In Physical Chemistry Chemical Physics 22(17). p.9195-9203
Abstract

Phytochromes are photosensory proteins in plants, fungi, and bacteria, which detect red- and far-red light. They undergo a transition between the resting (Pr) and photoactivated (Pfr) states. In bacterial phytochromes, the Pr-to-Pfr transition is facilitated by two intermediate states, called Lumi-R and Meta-R. The molecular structures of the protein in these states are not known and the molecular mechanism of photoconversion is not understood. Here, we apply transient infrared absorption spectroscopy to study the photocycle of the wild-type and Y263F mutant of the phytochrome from Deinococcus radiodurans (DrBphP) from nano- to milliseconds. We identify two sequentially forming Lumi-R states which differ in the local structure... (More)

Phytochromes are photosensory proteins in plants, fungi, and bacteria, which detect red- and far-red light. They undergo a transition between the resting (Pr) and photoactivated (Pfr) states. In bacterial phytochromes, the Pr-to-Pfr transition is facilitated by two intermediate states, called Lumi-R and Meta-R. The molecular structures of the protein in these states are not known and the molecular mechanism of photoconversion is not understood. Here, we apply transient infrared absorption spectroscopy to study the photocycle of the wild-type and Y263F mutant of the phytochrome from Deinococcus radiodurans (DrBphP) from nano- to milliseconds. We identify two sequentially forming Lumi-R states which differ in the local structure surrounding the carbonyl group of the biliverdin D-ring. We also find that the tyrosine at position 263 alters local structure and dynamics around the D-ring and causes an increased rate of Pfr formation. The results shed new light on the mechanism of light-signalling in phytochrome proteins.

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author
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publishing date
type
Contribution to journal
publication status
published
subject
in
Physical Chemistry Chemical Physics
volume
22
issue
17
pages
9 pages
publisher
Royal Society of Chemistry
external identifiers
  • pmid:32149285
  • scopus:85084270899
ISSN
1463-9076
DOI
10.1039/c9cp06995j
language
English
LU publication?
no
additional info
Publisher Copyright: © the Owner Societies.
id
7818c221-50c6-4193-8dd1-2bdfe89b4007
date added to LUP
2023-06-16 10:38:29
date last changed
2024-03-22 21:36:43
@article{7818c221-50c6-4193-8dd1-2bdfe89b4007,
  abstract     = {{<p>Phytochromes are photosensory proteins in plants, fungi, and bacteria, which detect red- and far-red light. They undergo a transition between the resting (Pr) and photoactivated (Pfr) states. In bacterial phytochromes, the Pr-to-Pfr transition is facilitated by two intermediate states, called Lumi-R and Meta-R. The molecular structures of the protein in these states are not known and the molecular mechanism of photoconversion is not understood. Here, we apply transient infrared absorption spectroscopy to study the photocycle of the wild-type and Y263F mutant of the phytochrome from Deinococcus radiodurans (DrBphP) from nano- to milliseconds. We identify two sequentially forming Lumi-R states which differ in the local structure surrounding the carbonyl group of the biliverdin D-ring. We also find that the tyrosine at position 263 alters local structure and dynamics around the D-ring and causes an increased rate of Pfr formation. The results shed new light on the mechanism of light-signalling in phytochrome proteins.</p>}},
  author       = {{Kübel, Joachim and Chenchiliyan, Manoop and Ooi, Saik Ann and Gustavsson, Emil and Isaksson, Linnéa and Kuznetsova, Valentyna and Ihalainen, Janne A. and Westenhoff, Sebastian and Maj, Michał}},
  issn         = {{1463-9076}},
  language     = {{eng}},
  month        = {{05}},
  number       = {{17}},
  pages        = {{9195--9203}},
  publisher    = {{Royal Society of Chemistry}},
  series       = {{Physical Chemistry Chemical Physics}},
  title        = {{Transient IR spectroscopy identifies key interactions and unravels new intermediates in the photocycle of a bacterial phytochrome}},
  url          = {{http://dx.doi.org/10.1039/c9cp06995j}},
  doi          = {{10.1039/c9cp06995j}},
  volume       = {{22}},
  year         = {{2020}},
}