Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Protein Transport to the Stroma01:24

Protein Transport to the Stroma

2.1K
Chloroplasts are triple membrane structures with an outer membrane, an inner membrane, and a thylakoid membrane, each containing distinct metabolite transporters, membrane translocons, and enzymes. Appropriate sorting and translocating these proteins to their correct membrane systems is essential for chloroplast function.
Protein complexes called the translocon of the outer chloroplast membrane or TOC complex, and the translocon of the inner chloroplast membrane or TIC complex mediate the...
2.1K
Photoreceptors and Plant Responses to Light02:00

Photoreceptors and Plant Responses to Light

28.2K
Light plays a significant role in regulating the growth and development of plants. In addition to providing energy for photosynthesis, light provides other important cues to regulate a range of developmental and physiological responses in plants.
28.2K
Cell Signaling in Plants01:25

Cell Signaling in Plants

6.1K
Plant cells communicate to coordinate their cycle of growth, flowering and fruiting, and activities in roots, shoots, and leaves in response to the changing environmental conditions. Plant signaling is distinct from animal signaling. Plants primarily utilize enzyme-linked receptors, whereas the largest class of cell-surface receptors in animals are G-protein coupled receptors (GPCRs). Unlike animals, receptor tyrosine kinases are rare in plants. Instead, plants have a diverse class of...
6.1K
The Antenna Complex01:15

The Antenna Complex

7.4K
Plants and other photosynthetic organisms comprise pigments capable of absorption of direct sunlight. These pigments are present in the reaction center - the main site of photochemical reactions as well as in the antenna complex. Under average light conditions, the rate at which reaction center pigments absorb light is far below the electron transport chain's capacity. As a result, the reaction center alone cannot provide enough energy to drive photosynthesis. The photosynthetic efficiency can...
7.4K
Protein Transport to the Outer Chloroplast Membrane01:11

Protein Transport to the Outer Chloroplast Membrane

2.3K
Chloroplast outer membrane proteins encoded by the nucleus are synthesized in the cytosol. Soon after synthesis, they bind cytosolic factors such as 14-3-3 protein and the Hsp70 chaperones that keep these precursors in an unfolded state until their translocation.
Two models describe the mechanism of precursor recognition and entry across the outer membrane through the TOC complex. Model 1 suggests the newly synthesized precursor binds to the TOC receptor 159 and forms a complex.
2.3K
Biological Clocks and Seasonal Responses02:45

Biological Clocks and Seasonal Responses

41.4K
The circadian—or biological—clock is an intrinsic, timekeeping, molecular mechanism that allows plants to coordinate physiological activities over 24-hour cycles called circadian rhythms. Photoperiodism is a collective term for the biological responses of plants to variations in the relative lengths of dark and light periods. The period of light-exposure is called the photoperiod.
41.4K

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

<b>Review of the genus <i>Anterhynchium</i> de Saussure (Hymenoptera: Vespidae: Eumeninae) from Vietnam, with the description of a new species and a key to the Oriental species</b>.

Zootaxa·2026
Same author

Cryo-electron microscopy structures of human cone visual pigments.

Science (New York, N.Y.)·2026
Same author

Ultrarapid MC1R protein and associated plumage color evolution in the domestic chicken.

Proceedings of the National Academy of Sciences of the United States of America·2026
Same author

Structure-Activity Relationship Study of Antimicrobial Peptide with Cross-Kingdom Activity.

Biochemistry·2026
Same author

Rural physician deployment programs in five Southeast Asian countries: a policy and narrative review.

BMC health services research·2026
Same author

Empowering Rural Caregivers Through Participatory Design: Lessons from the 3WINpA Project.

Studies in health technology and informatics·2026

Related Experiment Video

Updated: Dec 28, 2025

Proton Transfer and Protein Conformation Dynamics in Photosensitive Proteins by Time-resolved Step-scan Fourier-transform Infrared Spectroscopy
10:03

Proton Transfer and Protein Conformation Dynamics in Photosensitive Proteins by Time-resolved Step-scan Fourier-transform Infrared Spectroscopy

Published on: June 27, 2014

18.3K

Intramolecular Proton Transfer Controls Protein Structural Changes in Phytochrome.

Anastasia Kraskov1, Anh Duc Nguyen1, Jan Goerling1

  • 1Technische Universität Berlin, Institut für Chemie, Sekr. PC14, Straße des 17. Juni 135, D-10623 Berlin, Germany.

Biochemistry
|February 20, 2020
PubMed
Summary
This summary is machine-generated.

Key residues Arg211 and Tyr165 are essential for phytochrome photoconversion, blocking the process before structural changes. Deprotonation of the biliverdin chromophore is crucial for downstream protein restructuring.

More Related Videos

Atomic Force Microscopy of Red-Light Photoreceptors Using PeakForce Quantitative Nanomechanical Property Mapping
14:13

Atomic Force Microscopy of Red-Light Photoreceptors Using PeakForce Quantitative Nanomechanical Property Mapping

Published on: October 24, 2014

12.1K
Separation of Spinach Thylakoid Protein Complexes by Native Green Gel Electrophoresis and Band Characterization using Time-Correlated Single Photon Counting
08:40

Separation of Spinach Thylakoid Protein Complexes by Native Green Gel Electrophoresis and Band Characterization using Time-Correlated Single Photon Counting

Published on: February 14, 2019

8.6K

Related Experiment Videos

Last Updated: Dec 28, 2025

Proton Transfer and Protein Conformation Dynamics in Photosensitive Proteins by Time-resolved Step-scan Fourier-transform Infrared Spectroscopy
10:03

Proton Transfer and Protein Conformation Dynamics in Photosensitive Proteins by Time-resolved Step-scan Fourier-transform Infrared Spectroscopy

Published on: June 27, 2014

18.3K
Atomic Force Microscopy of Red-Light Photoreceptors Using PeakForce Quantitative Nanomechanical Property Mapping
14:13

Atomic Force Microscopy of Red-Light Photoreceptors Using PeakForce Quantitative Nanomechanical Property Mapping

Published on: October 24, 2014

12.1K
Separation of Spinach Thylakoid Protein Complexes by Native Green Gel Electrophoresis and Band Characterization using Time-Correlated Single Photon Counting
08:40

Separation of Spinach Thylakoid Protein Complexes by Native Green Gel Electrophoresis and Band Characterization using Time-Correlated Single Photon Counting

Published on: February 14, 2019

8.6K

Area of Science:

  • Biochemistry
  • Photochemistry
  • Structural Biology

Background:

  • Phytochromes are photoreceptors that regulate biological processes through light-dependent structural changes.
  • Bacteriophytochromes, like Agp2, possess a unique 'bathy' form where Pfr is the stable state.
  • The Pfr-to-Pr photoconversion involves chromophore isomerization and protein structural rearrangements, including a tongue segment transition.

Purpose of the Study:

  • To investigate the roles of specific amino acid residues (Arg211, Tyr165, His278, Phe192) near the biliverdin chromophore in the Pfr-to-Pr photoconversion of bathy bacteriophytochrome Agp2.
  • To elucidate the sequence of events, particularly the involvement of chromophore deprotonation and tongue restructuring, during this photoconversion process.

Main Methods:

  • Spectroscopic techniques were employed to analyze the structural and functional consequences of site-directed mutagenesis.
  • The study focused on substitutions of key residues and their impact on the biliverdin chromophore and phytochrome structure.

Main Results:

  • Substitutions of Arg211 or Tyr165 prevented photoconversion in the Meta-F state, prior to tongue restructuring and propC deprotonation.
  • These critical substitutions did not alter the biliverdin structure or Pfr properties but led to low photochemical activity in the Meta-F state.
  • While thermal back conversion was decelerated in all variants, substitutions of His278 or Phe192 did not impede Pfr-to-Pr photoconversion, propC deprotonation, or tongue restructuring.

Conclusions:

  • Arg211 and Tyr165 are crucial for initiating the Pfr-to-Pr photoconversion, acting before the secondary structure changes in the tongue.
  • Deprotonation of the biliverdin's propionic side chain (propC) is an essential prerequisite for the conformational changes in the phytochrome tongue segment.