title: Crystal Structure of Phototoxic Orange Fluorescent Proteins with a Tryptophan-Based Chromophore.
abstract: Phototoxic fluorescent proteins represent a sparse group of genetically encoded photosensitizers that could be used for precise light-induced inactivation of target proteins, DNA damage, and cell killing. Only two such GFP-based fluorescent proteins (FPs), KillerRed and its monomeric variant SuperNova, were described up to date. Here, we present a crystallographic study of their two orange successors, dimeric KillerOrange and monomeric mKillerOrange, at 1.81 and 1.57 Å resolution, respectively. They are the first orange-emitting protein photosensitizers with a tryptophan-based chromophore (Gln65-Trp66-Gly67). Same as their red progenitors, both orange photosensitizers have a water-filled channel connecting the chromophore to the β-barrel exterior and enabling transport of ROS. In both proteins, Trp66 of the chromophore adopts an unusual trans-cis conformation stabilized by H-bond with the nearby Gln159. This trans-cis conformation along with the water channel was shown to be a key structural feature providing bright orange emission and phototoxicity of both examined orange photosensitizers.
authors.affiliation: Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russian Federation.
authors.forename: Nadya V
authors.initials: NV
authors.lastname: Pletneva
authors.affiliation: Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russian Federation.
authors.forename: Vladimir Z
authors.initials: VZ
authors.lastname: Pletnev
authors.affiliation: Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russian Federation.
authors.forename: Karen S
authors.initials: KS
authors.lastname: Sarkisyan
authors.affiliation: Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russian Federation.|Faculty of Biology, Moscow State University, Moscow, Russian Federation.
authors.forename: Dmitry A
authors.initials: DA
authors.lastname: Gorbachev
authors.affiliation: Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russian Federation.
authors.forename: Evgeny S
authors.initials: ES
authors.lastname: Egorov
authors.affiliation: Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russian Federation.|Nizhny Novgorod State Medical Academy, Nizhny Novgorod, Russian Federation.
authors.forename: Alexander S
authors.initials: AS
authors.lastname: Mishin
authors.affiliation: Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russian Federation.|Nizhny Novgorod State Medical Academy, Nizhny Novgorod, Russian Federation.
authors.forename: Konstantin A
authors.initials: KA
authors.lastname: Lukyanov
authors.affiliation: Synchrotron Radiation Research Section, Macromolecular Crystallography Laboratory, National Cancer Institute, Argonne, Illinois, United States of America.
authors.forename: Zbigniew
authors.initials: Z
authors.lastname: Dauter
authors.affiliation: Synchrotron Radiation Research Section, Macromolecular Crystallography Laboratory, National Cancer Institute, Argonne, Illinois, United States of America.|Leidos Biomedical Research, Inc., Basic Research Program, Argonne, Illinois, United States of America.
authors.forename: Sergei
authors.initials: S
authors.lastname: Pletnev
mesh_terms: D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D018360:Crystallography, X-Ray; D008164:Luminescent Proteins / Q000737:chemistry* / Q000235:genetics; D008958:Models, Molecular; D008968:Molecular Conformation; D008969:Molecular Sequence Data; D016296:Mutagenesis; D009154:Mutation / Q000235:genetics; D055668:Photochemical Processes; D017319:Photosensitizing Agents / Q000737:chemistry*; D011487:Protein Conformation; D017386:Sequence Homology, Amino Acid; D014364:Tryptophan / Q000737:chemistry* / Q000235:genetics
chemical_list: D008164:Luminescent Proteins; D017319:Photosensitizing Agents; D014364:Tryptophan