title: A way to sense light intensity: Multiple-excitation of the BLUF photoreceptor TePixD suppresses conformational change.
abstract: TePixD, a cyanobacterial sensor of blue light using flavin adenine dinucleotide (FAD) (BLUF) which exists in a decamer form, was found to exhibit photoreaction sensitive to light intensity. While the number of excited molecules increased monotonically as the laser power increased, the number of decamers exhibiting a global conformational change initially increased, and then decreased with the increase of excitation intensity. This unusual power dependence was analyzed based on a Poisson distribution equation, demonstrating that decamers containing more than one excited monomer subunit do not undergo conformational change. Our results suggest that TePixD functions not only as a photosensor, but also by sensing light intensity.
authors.affiliation: Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan.
authors.forename: Keisuke
authors.initials: K
authors.lastname: Tanaka
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Nakasone
authors.forename: Koji
authors.initials: K
authors.lastname: Okajima
authors.forename: Masahiko
authors.initials: M
authors.lastname: Ikeuchi
authors.forename: Satoru
authors.initials: S
authors.lastname: Tokutomi
authors.forename: Masahide
authors.initials: M
authors.lastname: Terazima
mesh_terms: D000458:Cyanobacteria / Q000378:metabolism* / Q000528:radiation effects*; D007834:Lasers; D008027:Light; D055537:Light Signal Transduction / Q000528:radiation effects*; D020283:Photoreceptors, Microbial / Q000737:chemistry* / Q000378:metabolism*; D011487:Protein Conformation
chemical_list: D020283:Photoreceptors, Microbial