title: Isolation and characterization of light-regulated phycobilisome linker polypeptide genes and their transcription as a polycistronic mRNA.
abstract: Several cyanobacteria adjust both the phycobiliprotein and linker protein composition of the phycobilisome, a light-harvesting complex in cyanobacteria and some eucaryotic algae, to maximize absorption of prevalent wavelengths of light. This process is called complementary chromatic adaptation. We sequenced the amino terminus of a linker polypeptide which is associated with phycocyanin and accumulates to high levels during growth of the cyanobacterium Fremyella diplosiphon in red light. A mixed oligonucleotide encoding a region of this amino terminus was synthesized and used to identify a fragment of F. diplosiphon genomic DNA encoding the linker polypeptide. This linker gene was located between two other linker genes and contiguous to the red-light-induced phycocyanin gene set. Sequences of all three linker genes are presented. These genes were transcribed together onto a large polycistronic mRNA which also encoded the red-light-induced phycocyanin subunits. The relationship of this transcript to the biogenesis of the phycobilisome when F. diplosiphon is grown under different conditions of illumination is discussed.
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D003062:Codon; D000458:Cyanobacteria / Q000235:genetics*; D005786:Gene Expression Regulation / Q000528:radiation effects; D005796:Genes; D008027:Light; D045342:Light-Harvesting Protein Complexes; D009690:Nucleic Acid Conformation; D010788:Photosynthesis; D045524:Phycobilisomes; D010940:Plant Proteins / Q000235:genetics* / Q000502:physiology*; D012333:RNA, Messenger / Q000235:genetics; D014158:Transcription, Genetic
chemical_list: D003062:Codon; D045342:Light-Harvesting Protein Complexes; D045524:Phycobilisomes; D010940:Plant Proteins; D012333:RNA, Messenger