title: Genomic Survey and Biochemical Analysis of Recombinant Candidate Cyanobacteriochromes Reveals Enrichment for Near UV/Violet Sensors in the Halotolerant and Alkaliphilic Cyanobacterium Microcoleus IPPAS B353.
abstract: Cyanobacteriochromes (CBCRs), which are exclusive to and widespread among cyanobacteria, are photoproteins that sense the entire range of near-UV and visible light. CBCRs are related to the red/far-red phytochromes that utilize linear tetrapyrrole (bilin) chromophores. Best characterized from the unicellular cyanobacterium Synechocystis sp. PCC 6803 and the multicellular heterocyst forming filamentous cyanobacteria Nostoc punctiforme ATCC 29133 and Anabaena sp. PCC 7120, CBCRs have been poorly investigated in mat-forming, nonheterocystous cyanobacteria. In this study, we sequenced the genome of one of such species, Microcoleus IPPAS B353 (Microcoleus B353), and identified two phytochromes and seven CBCRs with one or more bilin-binding cGMP-specific phosphodiesterase, adenylyl cyclase and FhlA (GAF) domains. Biochemical and spectroscopic measurements of 23 purified GAF proteins from phycocyanobilin (PCB) producing recombinant Escherichia coli indicated that 13 of these proteins formed near-UV and visible light-absorbing covalent adducts: 10 GAFs contained PCB chromophores, whereas three contained the PCB isomer, phycoviolobilin (PVB). Furthermore, the complement of Microcoleus B353 CBCRs is enriched in near-UV and violet sensors, but lacks red/green and green/red CBCRs that are widely distributed in other cyanobacteria. We hypothesize that enrichment in short wavelength-absorbing CBCRs is critical for acclimation to high-light environments where this organism is found.
authors.affiliation: Department of Biological Sciences, Chungnam National University, Daejeon, 305-764, Korea.
authors.forename: Sung Mi
authors.initials: SM
authors.lastname: Cho
authors.affiliation: Center for Advanced Measurement and Instrumentation, Korea Research Institute of Standards and Science, Daejeon 305-340, Korea.
authors.forename: Sae Chae
authors.initials: SC
authors.lastname: Jeoung
authors.affiliation: Department of Biological Sciences, Chungnam National University, Daejeon, 305-764, Korea.
authors.forename: Ji-Young
authors.initials: JY
authors.lastname: Song
authors.affiliation: Institute of Plant Physiology, Russian Academy of Sciences, Botanicheskaya Street 35, Moscow 127276, Russia.
authors.forename: Elena V
authors.initials: EV
authors.lastname: Kupriyanova
authors.affiliation: Institute of Plant Physiology, Russian Academy of Sciences, Botanicheskaya Street 35, Moscow 127276, Russia.
authors.forename: Natalia A
authors.initials: NA
authors.lastname: Pronina
authors.affiliation: Seeders Inc., Daejeon, 305-509, Korea.
authors.forename: Bong-Woo
authors.initials: BW
authors.lastname: Lee
authors.affiliation: Seeders Inc., Daejeon, 305-509, Korea.
authors.forename: Seong-Whan
authors.initials: SW
authors.lastname: Jo
authors.affiliation: The Agricultural Genome Center, National Academy of Agricultural Science, Rural Development Administration, Wanju 565-851, Korea. Electronic address: yipark@cnu.ac.kr.
authors.forename: Beom-Seok
authors.initials: BS
authors.lastname: Park
authors.affiliation: School of Biotechnology and Environmental Engineering, Myongji University, Yongin 449-728, Korea.
authors.forename: Sang-Bong
authors.initials: SB
authors.lastname: Choi
authors.affiliation: Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon 305-701, Korea.
authors.forename: Ji-Joon
authors.initials: JJ
authors.lastname: Song
authors.affiliation: Department of Biological Sciences, Chungnam National University, Daejeon, 305-764, Korea.
authors.forename: Youn-Il
authors.initials: YI
authors.lastname: Park
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics*; D000458:Cyanobacteria / Q000235:genetics* / Q000378:metabolism; D016680:Genome, Bacterial; D018462:Photobiology; D014466:Ultraviolet Rays
chemical_list: D001426:Bacterial Proteins
keywords: Microcoleus; cyanobacteria; cyanobacteriochromes; genomics; nonheterocystous filamentous cyanobacterium; photobiology; photoreceptor; ultraviolet-visible spectroscopy (UV-Vis spectroscopy)