title: Duplication of the phycocyanin operon in the unicellular cyanobacterium Anacystis nidulans R2.
abstract: Two phycocyanin (PC) operons, each containing alpha- and beta-subunit genes, have been isolated from the unicellular cyanobacterium Anacystis nidulans R2. Using oligodeoxyribonucleotide probes for the PC-coding regions, three PstI fragments were obtained and shown to contain the two operons, which are 2.7 kb apart, with a proposed gene order of 5'-(beta I-alpha I)-(beta II-alpha II)-3'. The nucleotide sequences of both alpha-subunit genes are identical, as are the beta-sequences and the 51-bp intergenic regions. However, significant nucleotide sequence differences are found in both the 5' and 3' untranslated regions of the two operons. Two mRNA species of 1.65 and 1.5 kb were detected in A. nidulans R2 RNA when probed with either the alpha-specific or the beta-specific probe. The results demonstrate the existence of two PC operons which are both transcriptionally active.
authors.affiliation: Department of Botany, University of Toronto, Ontario, Canada.
authors.forename: R H
authors.initials: RH
authors.lastname: Lau
authors.forename: S D
authors.initials: SD
authors.lastname: Blakeley
authors.forename: G
authors.initials: G
authors.lastname: Alvarado-Urbina
authors.forename: J E
authors.initials: JE
authors.lastname: Bailly
authors.forename: J A
authors.initials: JA
authors.lastname: Condie
authors.forename: P C
authors.initials: PC
authors.lastname: Lau
mesh_terms: D001483:Base Sequence; D003001:Cloning, Molecular; D000458:Cyanobacteria / Q000235:genetics*; D008969:Molecular Sequence Data; D009876:Operon; D010798:Phycocyanin / Q000235:genetics*; D010860:Pigments, Biological / Q000235:genetics*; D014158:Transcription, Genetic
chemical_list: D010860:Pigments, Biological; D010798:Phycocyanin