title: Complete sequence and analysis of the plastid genome of the unicellular red alga Cyanidioschyzon merolae.
abstract: The complete nucleotide sequence of the plastid genome of the unicellular primitive red alga Cyanidioschyzon merolae 10D (Cyanidiophyceae) was determined. The genome is a circular DNA composed of 149,987 bp with no inverted repeats. The G + C content of this plastid genome is 37.6%. The C. merolae plastid genome contains 243 genes, which are distributed on both strands and consist of 36 RNA genes (3 rRNAs, 31 tRNAs, tmRNA, and a ribonuclease P RNA component) and 207 protein genes, including unidentified open reading frames. The striking feature of this genome is the high degree of gene compaction; it has very short intergenic distances (approximately 40% of the protein genes were overlapped) and no genes have introns. This genome encodes several genes that are rarely found in other plastid genomes. A gene encoding a subunit of sulfate transporter (cysW) is the first to be identified in a plastid genome. The cysT and cysW genes are located in the C. merolae plastid genome in series, and they probably function together with other nuclear-encoded components of the sulfate transport system. Our phylogenetic results suggest that the Cyanidiophyceae, including C. merolae, are a basal clade within the red lineage plastids.
authors.affiliation: Department of Molecular Biology, Faculty of Science, Saitama University, 255 Shimo-Ohkubo, Sakura, Saitama, Saitama 338-8570, Japan. niji@molbiol.saitama-u.ac.jp
authors.forename: Niji
authors.initials: N
authors.lastname: Ohta
authors.forename: Motomichi
authors.initials: M
authors.lastname: Matsuzaki
authors.forename: Osami
authors.initials: O
authors.lastname: Misumi
authors.forename: Shin-ya
authors.initials: SY
authors.lastname: Miyagishima
authors.forename: Hisayoshi
authors.initials: H
authors.lastname: Nozaki
authors.forename: Kan
authors.initials: K
authors.lastname: Tanaka
authors.forename: Tadasu
authors.initials: T
authors.lastname: Shin-I
authors.forename: Yuji
authors.initials: Y
authors.lastname: Kohara
authors.forename: Tsuneyoshi
authors.initials: T
authors.lastname: Kuroiwa
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D015723:Gene Library; D018745:Genome, Plant; D008957:Models, Genetic; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D010802:Phylogeny; D018087:Plastids / Q000235:genetics*; D012335:RNA, Ribosomal / Q000235:genetics; D012343:RNA, Transfer / Q000235:genetics; D000461:Rhodophyta / Q000235:genetics*; D017422:Sequence Analysis, DNA
chemical_list: D012335:RNA, Ribosomal; D012343:RNA, Transfer