Light-dependent dimerisation in the N-terminal sensory module of cyanobacterial phytochrome 1.
Phytochromes, photoreceptors controlling important physiological processes in plants and many prokaryotes, are photochromic biliproteins. The red-absorbing Pr ground state is converted by light into the farred-absorbing Pfr which can be photoconverted back to Pr. In plants at least Pfr is the physiologically active signalling state. Here, we show that the N-terminal photochromic module of Cph1 homodimerises reversibly and independently in Pr and Pfr, Pfr-dimers being significantly more stable. Implications for the mechanism of signal transduction are discussed.
Strauss
Holger M
HM
Forschungsinstitut für Molekulare Pharmakologie, Robert-Rössle Strasse 10, D-13125 Berlin, Germany. strauss@fmp-berlin.de
Schmieder
Peter
P
Hughes
Jon
J
D019540:Area Under Curve; D055592:Biophysical Phenomena; D001703:Biophysics; D002845:Chromatography; D002850:Chromatography, Gel; D000458:Cyanobacteria / Q000378:metabolism*; D019281:Dimerization; D004305:Dose-Response Relationship, Drug; D020407:Internet; D007700:Kinetics; D008027:Light; D046911:Macromolecular Substances / Q000737:chemistry; D010777:Photochemistry; D010786:Photoreceptor Cells / Q000378:metabolism; D010834:Phytochrome / Q000737:chemistry*; D020836:Protein Structure, Quaternary; D017434:Protein Structure, Tertiary; D012542:Scattering, Radiation; D015398:Signal Transduction; D014461:Ultracentrifugation
D046911:Macromolecular Substances; D010834:Phytochrome