Related Experiment Video
Updated: Aug 27, 2026

In Vitro Reconstitution of Light-harvesting Complexes of Plants and Green Algae
Published on: October 10, 2014
Functional Characterization of Conserved Positively Charged Residues Surrounding the Ligand-Binding Pocket in Plant
Mengqi Wan1, Hao Liu1, Jiaying Zhang1
1Department of Biochemistry and Molecular Biology, School of Basic Medicine, Wannan Medical College, Wuhu, Anhui, China.
Abstract:
Plant cryptochromes are blue light-responsive photoreceptor proteins that regulate various photoresponses throughout plant growth and development. Compared with their homologous CPD I/III photolyases, plant cryptochromes have lost DNA repair activity but evolved signal transduction functions. The structurally conserved ligand-binding pocket, which corresponds to the photolyase active site, exhibits distinctive features in plant cryptochromes, with key binding residues being altered relative to photolyases. Notably, the distribution of charged amino acids around this pocket differs markedly between the two protein families. In this study, we identified two conserved positively charged residues (Arg237 and Arg357) flanking this pocket in Chlamydomonas reinhardtii cryptochrome (pCRY) and its Arabidopsis homologs. Biochemical and physiological analyses demonstrated that these residues effectively modulate photoreduction kinetics and oxidative stability of the flavin adenine dinucleotide (FAD) cofactor, participate in ATP binding, and ultimately influence flowering time in transgenic Arabidopsis plants. Our findings reveal that these conserved positively charged sites play critical roles in regulating the photosensitivity and functional stability of plant cryptochromes.
More Related Videos
14:02Optimizing the Genetic Incorporation of Chemical Probes into GPCRs for Photo-crosslinking Mapping and Bioorthogonal Chemistry in Live Mammalian Cells
Published on: April 9, 2018
11:10Protein-protein Interactions Visualized by Bimolecular Fluorescence Complementation in Tobacco Protoplasts and Leaves
Published on: March 9, 2014
Related Concept Videos
Conserved Binding Sites
Binding sites are often located in large pockets, and if their location on a protein’s surface is unknown, it can be predicted using various approaches. The energetic method computationally analyses the...
Cell Signaling in Plants
Ligand Binding Sites
Protein-ligand interactions are quite specific; even though numerous potential ligands surround a cellular protein at any given time, only a particular ligand can bind to that protein. Moreover, a ligand binds only to a dedicated area on the surface of the protein, known as the...
Protein Transport to the Inner Chloroplast Membrane
Channel Rhodopsins
Rhodopsins belong to the family of cell surface proteins called G-protein coupled receptors,...
Crystal Field Theory - Octahedral Complexes
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...