2v1b
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N- AND C-TERMINAL HELICES OF OAT LOV2 (404-546) ARE INVOLVED IN LIGHT-INDUCED SIGNAL TRANSDUCTION (ROOM TEMPERATURE (293K) LIGHT STRUCTURE OF LOV2 (404-546))
OverviewOverview
Light sensing by photoreceptors controls phototropism, chloroplast movement, stomatal opening, and leaf expansion in plants. Understanding the molecular mechanism by which these processes are regulated requires a quantitative description of photoreceptor dynamics. We focus on a light-driven signal transduction mechanism in the LOV2 domain (LOV, light, oxygen, voltage) of the blue light photoreceptor phototropin 1 from Avena sativa (oat). High-resolution crystal structures of the dark and light states of an oat LOV2 construct including residues Leu404 through Leu546 (LOV2 (404-546)) have been determined at 105 and 293 K. In all four structures, LOV2 (404-546) exhibits the typical Per-ARNT-Sim (PAS) fold, flanked by an additional conserved N-terminal turn-helix-turn motif and a C-terminal flanking region containing an amphipathic Jalpha helix. These regions dock on the LOV2 core domain and bury several hydrophobic residues of the central beta-sheet of the core domain that would otherwise be exposed to solvent. Light structures of LOV2 (404-546) reveal that formation of the covalent bond between Cys450 and the C4a atom of the flavin mononucleotide (FMN) results in local rearrangement of the hydrogen-bonding network in the FMN binding pocket. These rearrangements are associated with disruption of the Asn414-Asp515 hydrogen bond on the surface of the protein and displacement of the N- and C-terminal flanking regions of LOV2 (404-546), both of which constitute a structural signal.
About this StructureAbout this Structure
2V1B is a Single protein structure of sequence from Avena sativa with and as ligands. Known structural/functional Sites: and . Full crystallographic information is available from OCA.
ReferenceReference
N- and C-terminal flanking regions modulate light-induced signal transduction in the LOV2 domain of the blue light sensor phototropin 1 from Avena sativa., Halavaty AS, Moffat K, Biochemistry. 2007 Dec 11;46(49):14001-9. Epub 2007 Nov 15. PMID:18001137
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