title: A biliverdin-binding cyanobacteriochrome from the chlorophyll d-bearing cyanobacterium Acaryochloris marina.
abstract: Cyanobacteriochromes (CBCRs) are linear tetrapyrrole-binding photoreceptors in cyanobacteria that absorb visible and near-ultraviolet light. CBCRs are divided into two types based on the type of chromophore they contain: phycocyanobilin (PCB) or phycoviolobilin (PVB). PCB-binding CBCRs reversibly photoconvert at relatively long wavelengths, i.e., the blue-to-red region, whereas PVB-binding CBCRs reversibly photoconvert at shorter wavelengths, i.e., the near-ultraviolet to green region. Notably, prior to this report, CBCRs containing biliverdin (BV), which absorbs at longer wavelengths than do PCB and PVB, have not been found. Herein, we report that the typical red/green CBCR AM1_1557 from the chlorophyll d-bearing cyanobacterium Acaryochloris marina can bind BV almost comparable to PCB. This BV-bound holoprotein reversibly photoconverts between a far red light-absorbing form (Pfr, λmax = 697 nm) and an orange light-absorbing form (Po, λmax = 622 nm). At room temperature, Pfr fluoresces with a maximum at 730 nm. These spectral features are red-shifted by 48~77 nm compared with those of the PCB-bound domain. Because the absorbance of chlorophyll d is red-shifted compared with that of chlorophyll a, the BV-bound AM1_1557 may be a physiologically relevant feature of A. marina and is potentially useful as an optogenetic switch and/or fluorescence imager.
authors.affiliation: 1] Department of Biological Science, Faculty of Science, Shizuoka University, Ohya, Suruga-ku, Shizuoka 422-8529, Japan [2] Graduate School of Art and Sciences, University of Tokyo, Komaba, Meguro, Tokyo 153-8902, Japan [3] Precursory Research for Embryonic Science and Technology, Japan Science and Technology Agency, 4-1-8 Honcho Kawaguchi, Saitama 332-0012 Japan.
authors.forename: Rei
authors.initials: R
authors.lastname: Narikawa
authors.affiliation: Graduate School of Art and Sciences, University of Tokyo, Komaba, Meguro, Tokyo 153-8902, Japan.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Nakajima
authors.affiliation: Graduate School of Art and Sciences, University of Tokyo, Komaba, Meguro, Tokyo 153-8902, Japan.
authors.forename: Yuki
authors.initials: Y
authors.lastname: Aono
authors.affiliation: Department of Biological Science, Faculty of Science, Shizuoka University, Ohya, Suruga-ku, Shizuoka 422-8529, Japan.
authors.forename: Keiji
authors.initials: K
authors.lastname: Fushimi
authors.affiliation: Graduate School of Art and Sciences, University of Tokyo, Komaba, Meguro, Tokyo 153-8902, Japan.
authors.forename: Gen
authors.initials: G
authors.lastname: Enomoto
authors.affiliation: Graduate School of Art and Sciences, University of Tokyo, Komaba, Meguro, Tokyo 153-8902, Japan.
authors.lastname: Ni-Ni-Win
authors.affiliation: Division of Material Science, Graduate School of Science, Nagoya University, Nagoya 464-8602, Japan.
authors.forename: Shigeru
authors.initials: S
authors.lastname: Itoh
authors.affiliation: Graduate School of Art and Sciences, University of Tokyo, Komaba, Meguro, Tokyo 153-8902, Japan.
authors.forename: Moritoshi
authors.initials: M
authors.lastname: Sato
authors.affiliation: 1] Graduate School of Art and Sciences, University of Tokyo, Komaba, Meguro, Tokyo 153-8902, Japan [2] Core Research for Evolutional Science and Technology, Japan Science and Technology Agency, 4-1-8 Honcho Kawaguchi, Saitama 332-0012 Japan.
authors.forename: Masahiko
authors.initials: M
authors.lastname: Ikeuchi
mesh_terms: D001664:Biliverdine / Q000737:chemistry / Q000378:metabolism*; D002734:Chlorophyll / Q000737:chemistry / Q000378:metabolism*; D000458:Cyanobacteria / Q000378:metabolism; D008027:Light; D020283:Photoreceptors, Microbial / Q000737:chemistry / Q000378:metabolism; D052980:Phycobilins / Q000737:chemistry / Q000378:metabolism*; D010798:Phycocyanin / Q000737:chemistry / Q000378:metabolism*; D011485:Protein Binding
chemical_list: D020283:Photoreceptors, Microbial; D052980:Phycobilins; C526232:phycoviolobilin; D010798:Phycocyanin; D002734:Chlorophyll; C011069:phycocyanobilin; C107509:chlorophyll d; D001664:Biliverdine