title: Complete chloroplast DNA sequence of the moss Physcomitrella patens: evidence for the loss and relocation of rpoA from the chloroplast to the nucleus.
abstract: The complete chloroplast DNA sequence (122 890 bp) of the moss Physcomitrella patens has been determined. The genome contains 83 protein, 31 tRNA and four rRNA genes, and a pseudogene. Four protein genes (rpoA, cysA, cysT and ccsA) found in the liverwort Marchantia polymorpha and the hornwort Anthoceros formosae are absent from P.patens. The overall structure of P.patens chloroplast DNA (cpDNA) differs substantially from that of liverwort and hornwort. Compared with its close relatives, a 71 kb region from petD to rpoB of P.patens is inverted. To investigate whether this large inversion and the loss of rpoA usually occur in moss plants, we analyzed amplified cpDNA fragments from four moss species. Our data indicate that the large inversion occurs only in P.patens, whereas the loss of the rpoA gene occurs in all mosses. Moreover, we have isolated and characterized the nuclear rpoA gene encoding the alpha subunit of RNA polymerase (RNAP) from P.patens and examined its subcellular localization. When fused to green fluorescent protein, RpoA was observed in the chloroplasts of live moss protonemata cells. This indicates that chloroplast RNAP is encoded separately by chloroplast and nuclear genomes in the moss. These data provide new insights into the regulation and evolution of chloroplast transcription.
authors.affiliation: Center for Gene Research, Nagoya University, Chikusa, Nagoya 464-8602, Japan.
authors.forename: Chika
authors.initials: C
authors.lastname: Sugiura
authors.forename: Yuki
authors.initials: Y
authors.lastname: Kobayashi
authors.forename: Setsuyuki
authors.initials: S
authors.lastname: Aoki
authors.forename: Chieko
authors.initials: C
authors.lastname: Sugita
authors.forename: Mamoru
authors.initials: M
authors.lastname: Sugita
mesh_terms: D000595:Amino Acid Sequence; D019068:Bryopsida / Q000235:genetics*; D002467:Cell Nucleus / Q000235:genetics; D002736:Chloroplasts / Q000235:genetics / Q000378:metabolism; D002874:Chromosome Mapping; D018742:DNA, Chloroplast / Q000737:chemistry / Q000235:genetics*; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics; D018744:DNA, Plant / Q000737:chemistry / Q000235:genetics; D012321:DNA-Directed RNA Polymerases / Q000235:genetics / Q000378:metabolism; D049452:Green Fluorescent Proteins; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism; D008856:Microscopy, Fluorescence; D008969:Molecular Sequence Data; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid
chemical_list: D018742:DNA, Chloroplast; D018076:DNA, Complementary; D018744:DNA, Plant; D008164:Luminescent Proteins; D011993:Recombinant Fusion Proteins; D049452:Green Fluorescent Proteins; D012321:DNA-Directed RNA Polymerases; C113275:RNA polymerase alpha subunit