1G28

STRUCTURE OF A FLAVIN-BINDING DOMAIN, LOV2, FROM THE CHIMERIC PHYTOCHROME/PHOTOTROPIN PHOTORECEPTOR PHY3

Summary for 1G28

• Entry DOI: 10.2210/pdb1g28/pdb
• Descriptor: PHY3 PROTEIN, FLAVIN MONONUCLEOTIDE (3 entities in total)
• Functional Keywords: phototropin, lov, pas fold, photoreceptor, flavoprotein, fmn-binding domain, alpha-beta structure, signaling protein, electron transport
• Biological source: Adiantum capillus-veneris
• Total number of polymer chains: 4
• Total formula weight: 50552.43

Authors

Crosson, S.,Moffat, K. (deposition date: 2000-10-17, release date: 2001-03-21, Last modification date: 2024-02-07)

Primary citation

Crosson, S.,Moffat, K.
Structure of a flavin-binding plant photoreceptor domain: insights into light-mediated signal transduction
Proc.Natl.Acad.Sci.USA, 98:2995-3000, 2001

PubMed Abstract: Phototropin, a major blue-light receptor for phototropism in seed plants, exhibits blue-light-dependent autophosphorylation and contains two light, oxygen, or voltage (LOV) domains and a serine/threonine kinase domain. The LOV domains share homology with the PER-ARNT-SIM (PAS) superfamily, a diverse group of sensor proteins. Each LOV domain noncovalently binds a single FMN molecule and exhibits reversible photochemistry in vitro when expressed separately or in tandem. We have determined the crystal structure of the LOV2 domain from the phototropin segment of the chimeric fern photoreceptor phy3 to 2.7-A resolution. The structure constitutes an FMN-binding fold that reveals how the flavin cofactor is embedded in the protein. The single LOV2 cysteine residue is located 4.2 A from flavin atom C(4a), consistent with a model in which absorption of blue light induces formation of a covalent cysteinyl-C(4a) adduct. Residues that interact with FMN in the phototropin segment of the chimeric fern photoreceptor (phy3) LOV2 are conserved in LOV domains from phototropin of other plant species and from three proteins involved in the regulation of circadian rhythms in Arabidopsis and Neurospora. This conservation suggests that these domains exhibit the same overall fold and share a common mechanism for flavin binding and light-induced signaling.

PubMed: 11248020
DOI: 10.1073/pnas.051520298

Experimental method

X-RAY DIFFRACTION (2.73 Å)