title: An unusual organization of the genes encoding cytochrome b559 in Chlamydomonas reinhardtii: psbE and psbF genes are separately transcribed from different regions of the plastid chromosome.
abstract: The psbE and psbF genes encode the apoproteins of cytochrome b559, an essential component of the pigment protein complex photosystem II. Together with psbL and psbJ, these genes constitute a single operon in all photosynthetic organisms examined thus far. We have cloned and sequenced the psbE and psbF genes of the Chlamydomonas reinhardtii plastid genome. The predicted amino-terminal domains of both polypeptides are more basic than those of other organisms, and the sequence of the psbE gene product indicates a departure from the 'positive-inside' rule for the insertion of proteins in the thylakoid membrane. Northern blot analysis demonstrated that psbE is transcribed into a 0.3 kb mRNA, while transcription of psbF and psbL genes results in a 0.9 kb transcript. The splitting of the psbEFLJ operon into separate transcription units suggests a unique mechanism of regulation of expression of these genes in C. reinhardtii.
authors.affiliation: Department of Biological Chemistry, Hebrew University of Jerusalem, Israel.
authors.forename: T S
authors.initials: TS
authors.lastname: Mor
authors.forename: I
authors.initials: I
authors.lastname: Ohad
authors.forename: J
authors.initials: J
authors.lastname: Hirschberg
authors.forename: H B
authors.initials: HB
authors.lastname: Pakrasi
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001059:Apoproteins / Q000737:chemistry / Q000235:genetics*; D001483:Base Sequence; D016825:Chlamydomonas reinhardtii / Q000235:genetics*; D003001:Cloning, Molecular; D003573:Cytochrome b Group / Q000737:chemistry / Q000235:genetics*; D017125:Genes, Protozoan / Q000235:genetics*; D008969:Molecular Sequence Data; D009876:Operon / Q000235:genetics; D045332:Photosystem II Protein Complex; D018087:Plastids / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics; D016053:RNA, Protozoan / Q000235:genetics; D015183:Restriction Mapping; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D014158:Transcription, Genetic / Q000235:genetics*
chemical_list: D001059:Apoproteins; D003573:Cytochrome b Group; D045332:Photosystem II Protein Complex; D012333:RNA, Messenger; D016053:RNA, Protozoan; C019313:cytochrome b559