title: Identification of an oxygenic reaction center psbADC operon in the cyanobacterium Gloeobacter violaceus PCC 7421.
abstract: Gloeobacter violaceus, the earliest diverging oxyphotobacterium (cyanobacterium) on the 16S ribosomal RNA tree, has five copies of the photosystem II psbA gene encoding the D1 reaction center protein subunit. These copies are widely distributed throughout the 4.6 Mbp genome with only one copy colocalizing with other PSII subunits, in marked contrast to all other psbA genes in all publicly available sequenced genomes. A clustering of two other psb genes around psbA3 (glr2322) is unique to Gloeobacter. We provide experimental proof for the transcription of a psbA3DC operon, encoding three of the five reaction center core subunits (D1, D2, and CP43). This is the first example of a transcribed gene cluster containing the D1/D2 or D1/D2/CP43 subunits of PSII in an oxygenic phototroph (prokaryotic or eukaryotic). Implications for the evolution of oxygenic photosynthesis are discussed.
authors: Tuan A
authors: TA
authors: Nguyen
authors: Jasmina
authors: J
authors: Brescic
authors: David J
authors: DJ
authors: Vinyard
authors: Thenappan
authors: T
authors: Chandrasekar
authors: G Charles
authors: GC
authors: Dismukes
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D000458:Cyanobacteria / Q000235:genetics* / Q000378:metabolism; D019143:Evolution, Molecular; D008957:Models, Genetic; D005810:Multigene Family; D009876:Operon; D010100:Oxygen / Q000378:metabolism*; D010788:Photosynthesis / Q000235:genetics; D045332:Photosystem II Protein Complex / Q000235:genetics* / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D045332:Photosystem II Protein Complex; C422369:photosystem II, psbA subunit; C085993:psbDI protein, cyanobacteria; D010100:Oxygen