title: Structural characterization of the photoswitchable fluorescent protein Dronpa-C62S.
abstract: The photoswitching behavior of green fluorescent proteins (GFPs) or GFP-like proteins is increasingly recognized as a new technique for optical marking. Recently, Ando and his colleagues developed a new green fluorescent protein Dronpa, which possesses the unique photochromic property of being photoswitchable in a non-destructive manner. To better understand this mechanism, we determined the crystal structures of a new GFP Dronpa and its mutant C62S, at 1.9 Angstroms and 1.8 Angstroms, respectively. Determination of the structures demonstrates that a unique hydrogen-bonding network and the sulfur atom of the chromophore are critical to the photoswitching property of Dronpa. Reversible photoswitching was lost in cells expressing the Dronpa-C62S upon repetitive irradiation compared to the native protein. Structural and mutational analyses reveal the chemical basis for the functional properties of photoswitchable fluorescent proteins and provide the basis for subsequent coherent engineering of this subfamily of Dronpa homologs.
authors.affiliation: Division of Biotechnology, College of Life Sciences & Biotechnology, Korea University, Anam-Dong, Sungbuk-Gu, Seoul, South Korea.
authors.forename: Ki-Hyun
authors.initials: KH
authors.lastname: Nam
authors.forename: Oh Yeun
authors.initials: OY
authors.lastname: Kwon
authors.forename: Kanako
authors.initials: K
authors.lastname: Sugiyama
authors.forename: Won-Ho
authors.initials: WH
authors.lastname: Lee
authors.forename: Young Kwan
authors.initials: YK
authors.lastname: Kim
authors.forename: Hyun Kyu
authors.initials: HK
authors.lastname: Song
authors.forename: Eunice Eunkyung
authors.initials: EE
authors.lastname: Kim
authors.forename: Sam-Yong
authors.initials: SY
authors.lastname: Park
authors.forename: Hyesung
authors.initials: H
authors.lastname: Jeon
authors.forename: Kwang Yeon
authors.initials: KY
authors.lastname: Hwang
mesh_terms: D000818:Animals; D037421:Anthozoa; D003460:Crystallization; D018360:Crystallography, X-Ray; D049452:Green Fluorescent Proteins / Q000737:chemistry* / Q000235:genetics; D006860:Hydrogen Bonding; D008958:Models, Molecular
chemical_list: D049452:Green Fluorescent Proteins