title: Structure of a protein photocycle intermediate by millisecond time-resolved crystallography.
abstract: The blue-light photoreceptor photoactive yellow protein (PYP) undergoes a self-contained light cycle. The atomic structure of the bleached signaling intermediate in the light cycle of PYP was determined by millisecond time-resolved, multiwavelength Laue crystallography and simultaneous optical spectroscopy. Light-induced trans-to-cis isomerization of the 4-hydroxycinnamyl chromophore and coupled protein rearrangements produce a new set of active-site hydrogen bonds. An arginine gateway opens, allowing solvent exposure and protonation of the chromophore's phenolic oxygen. Resulting changes in shape, hydrogen bonding, and electrostatic potential at the protein surface form a likely basis for signal transduction. The structural results suggest a general framework for the interpretation of protein photocycles.
authors.affiliation: Department of Molecular Biology, Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA.
authors.forename: U K
authors.initials: UK
authors.lastname: Genick
authors.forename: G E
authors.initials: GE
authors.lastname: Borgstahl
authors.forename: K
authors.initials: K
authors.lastname: Ng
authors.forename: Z
authors.initials: Z
authors.lastname: Ren
authors.forename: C
authors.initials: C
authors.lastname: Pradervand
authors.forename: P M
authors.initials: PM
authors.lastname: Burke
authors.forename: V
authors.initials: V
authors.lastname: Srajer
authors.forename: T Y
authors.initials: TY
authors.lastname: Teng
authors.forename: W
authors.initials: W
authors.lastname: Schildkamp
authors.forename: D E
authors.initials: DE
authors.lastname: McRee
authors.forename: K
authors.initials: K
authors.lastname: Moffat
authors.forename: E D
authors.initials: ED
authors.lastname: Getzoff
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry* / Q000502:physiology; D001665:Binding Sites; D002841:Chromatiaceae; D018360:Crystallography, X-Ray; D004563:Electrochemistry; D006860:Hydrogen Bonding; D007536:Isomerism; D008027:Light; D008958:Models, Molecular; D020283:Photoreceptors, Microbial; D011487:Protein Conformation; D015398:Signal Transduction; D013057:Spectrum Analysis
chemical_list: D001426:Bacterial Proteins; D020283:Photoreceptors, Microbial; C050162:photoactive yellow protein, Bacteria