title: Light-Induced Conformational Changes of LOV2-Kinase and the Linker Region in Arabidopsis Phototropin2.
abstract: Phototropins (phots) are blue light sensors found in a variety of higher plants and algae. The photochemical reactions of this family of proteins have attracted much attention since their discovery. Phots have two light sensor domains called light-oxygen-voltage 1 (LOV1) and LOV2. After the formation of the characteristic adduct of the LOV domain, a conformational change of the C-terminal region of the LOV2 domain occurs, and characterizing this change is important for understanding biological function, that is, kinase activation. Here, the reaction dynamics of the Jα-helix and the extended region adjacent to the Jα-helix (connector) have been investigated. The conformation of the connector part and the Jα-helix were found to alter significantly in a two-state manner. Furthermore, the conformational change of the kinase domain was also successfully detected as a change in translational diffusion, although the CD intensity due to the kinase domain movement was almost silent. These observations indicate that the tertiary structure of the kinase domain changes. The rate of the kinase domain change is almost the same as that of the change for the LOV2-linker, suggesting that the conformational change of the linker is the rate-determining step for kinase activation.
authors.affiliation: Department of Chemistry, Graduate School of Science, Kyoto University , Kyoto 606-8502, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Takakado
authors.affiliation: Department of Chemistry, Graduate School of Science, Kyoto University , Kyoto 606-8502, Japan.
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Nakasone
authors.affiliation: Department of Biological Science, Graduate School of Science, Osaka Prefecture University , Sakai, Osaka 599-8531, Japan.
authors.forename: Koji
authors.initials: K
authors.lastname: Okajima
authors.affiliation: Department of Biological Science, Graduate School of Science, Osaka Prefecture University , Sakai, Osaka 599-8531, Japan.
authors.forename: Satoru
authors.initials: S
authors.lastname: Tokutomi
authors.affiliation: Department of Chemistry, Graduate School of Science, Kyoto University , Kyoto 606-8502, Japan.
authors.forename: Masahide
authors.identifier: 0000-0001-6828-479X
authors.initials: M
authors.lastname: Terazima
mesh_terms: D029681:Arabidopsis Proteins / Q000737:chemistry*; D004268:DNA-Binding Proteins / Q000737:chemistry*; D008027:Light; D010770:Phosphotransferases / Q000737:chemistry* / Q000378:metabolism; D056949:Phototropins / Q000737:chemistry*; D011487:Protein Conformation
chemical_list: D029681:Arabidopsis Proteins; D004268:DNA-Binding Proteins; C000612094:LOV2 protein, Arabidopsis; D056949:Phototropins; D010770:Phosphotransferases