title: Structural communication between the chromophore-binding pocket and the N-terminal extension in plant phytochrome phyB.
abstract: The N-terminal extension (NTE) of plant phytochromes has been suggested to play a functional role in signaling photoinduced structural changes. Here, we use resonance Raman spectroscopy to study the effect of the NTE on the chromophore structure of B-type phytochromes from two evolutionarily distant plants. NTE deletion seems to have no effect on the chromophore in the inactive Pr state, but alters the torsion of the C-D ring methine bridge and the surrounding hydrogen bonding network in the physiologically active Pfr state. These changes are accompanied by a shift of the conformational equilibrium between two Pfr substates, which might affect the thermal isomerization rate of the C-D double bond and, thus, account for the effect of the NTE on the dark reversion kinetics.
authors.affiliation: Institut für Chemie, Technische Universität Berlin, Germany.
authors.forename: Francisco
authors.initials: F
authors.lastname: Velázquez Escobar
authors.affiliation: Institut für Chemie, Technische Universität Berlin, Germany.
authors.forename: David
authors.initials: D
authors.lastname: Buhrke
authors.affiliation: Institut für Chemie, Technische Universität Berlin, Germany.
authors.forename: Maria
authors.initials: M
authors.lastname: Fernandez Lopez
authors.affiliation: Plant Physiology, Justus-Liebig University Gießen, Giessen, Germany.
authors.forename: Sintayehu Manaye
authors.initials: SM
authors.lastname: Shenkutie
authors.affiliation: Fachbereich Chemie, Strukturbiochemie, Philipps-Universität Marburg, Marburg, Germany.
authors.forename: Silke
authors.initials: S
authors.lastname: von Horsten
authors.affiliation: Fachbereich Chemie, Strukturbiochemie, Philipps-Universität Marburg, Marburg, Germany.|LOEWE Center for Synthetic Microbiology, Philipps-Universität, Marburg, Germany.
authors.forename: Lars-Oliver
authors.initials: LO
authors.lastname: Essen
authors.affiliation: Plant Physiology, Justus-Liebig University Gießen, Giessen, Germany.
authors.forename: Jon
authors.initials: J
authors.lastname: Hughes
authors.affiliation: Institut für Chemie, Technische Universität Berlin, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Hildebrandt
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism; D001665:Binding Sites / Q000235:genetics; D006860:Hydrogen Bonding; D007700:Kinetics; D008027:Light; D008958:Models, Molecular; D009154:Mutation; D051939:Phytochrome B / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D010944:Plants / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding / Q000528:radiation effects; D000072417:Protein Domains; D045868:Sorghum / Q000235:genetics / Q000378:metabolism; D013059:Spectrum Analysis, Raman; D013816:Thermodynamics
chemical_list: D051939:Phytochrome B
keywords: N-terminal extension; chromophore structure; plant phytochrome; resonance Raman spectroscopy