title: Minicircular plastid DNA in the dinoflagellate Amphidinium operculatum.
abstract: Plastid DNA was purified from the dinoflagellate Amphidinium operculatum. The genes atpB, petD, psaA, psbA and psbB have been shown to reside on single-gene minicircles of a uniform size of 2.3-2.4 kb. The psaA and psbB genes lack conventional initiation codons in the expected positions, and may use GTA for translation initiation. There are marked biases in codon preference. The predicted PsbA protein lacks the C-terminal extension which is present in all other photosynthetic organisms except Euglena gracilis, and there are other anomalies elsewhere in the predicted amino acid sequences. The non-coding regions of the minicircles contain a "core" region which includes a number of stretches that are highly conserved across all minicircles and modular regions that are conserved within subsets of the minicircles.
authors.affiliation: Department of Biochemistry and Cambridge Centre for Molecular Recognition, University of Cambridge, UK. acb18@mole.bio.cam.ac.uk
authors.forename: A C
authors.initials: AC
authors.lastname: Barbrook
authors.forename: C J
authors.initials: CJ
authors.lastname: Howe
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics; D001483:Base Sequence; D003062:Codon / Q000235:genetics; D003573:Cytochrome b Group / Q000235:genetics; D045346:Cytochrome b6f Complex; D004270:DNA, Circular / Q000235:genetics* / Q000302:isolation & purification*; D016054:DNA, Protozoan / Q000235:genetics* / Q000302:isolation & purification*; D004141:Dinoflagellida / Q000235:genetics*; D017125:Genes, Protozoan; D045342:Light-Harvesting Protein Complexes; D008969:Molecular Sequence Data; D045322:Photosynthetic Reaction Center Complex Proteins / Q000235:genetics; D045331:Photosystem I Protein Complex; D045332:Photosystem II Protein Complex; D010802:Phylogeny; D018087:Plastids / Q000235:genetics*; D015800:Protozoan Proteins / Q000235:genetics; D017386:Sequence Homology, Amino Acid; D012689:Sequence Homology, Nucleic Acid
chemical_list: D001426:Bacterial Proteins; D003062:Codon; D003573:Cytochrome b Group; D004270:DNA, Circular; D016054:DNA, Protozoan; D045342:Light-Harvesting Protein Complexes; C073973:PSI-A protein, Synechococcus; D045322:Photosynthetic Reaction Center Complex Proteins; D045331:Photosystem I Protein Complex; D045332:Photosystem II Protein Complex; D015800:Protozoan Proteins; C084072:petD protein, cytochrome b(6)f complex; C070970:photosystem II, chlorophyll-binding protein, CP-47; D045346:Cytochrome b6f Complex