title: Amino acid sequence variations in Nicotiana CRR4 orthologs determine the species-specific efficiency of RNA editing in plastids.
abstract: In flowering plants, RNA editing is a posttranscriptional process that converts specific C to U in organelle mRNAs. Nicotiana tabacum is an allotetraploid species derived from the progenitors of Nicotiana sylvestris and Nicotiana tomentosiformis. These Nicotiana species have been used as a model for understanding the mechanism and evolution of RNA editing in plastids. In Nicotiana species, the ndhD-1 site is edited to create the translational initiation codon of ndhD that encodes a subunit of the NAD(P)H dehydrogenease (NDH) complex. An analysis of this RNA editing revealed that editing efficiency in N. tomentosiformis is lower (15%) than that in N. tabacum (42%) and N. sylvestris (37%). However, this level of editing is sufficient for accumulating the NDH complex and its activity. The heterogous complementation of Arabidopsis crr4-3 mutant, in which RNA editing of ndhD-1 is completely impaired, with CRR4 orthologous genes derived from Nicotiana species suggested that the reduction in editing efficiency in N. tomentosiformis is caused by amino acid variations accumulating in CRR4.
authors.affiliation: Department of Botany, Graduate School of Science, Kyoto University, Oiwake-cho, Kitashirakawa, Sakyo-ku, Kyoto 606-8502, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Okuda
authors.forename: Yuya
authors.initials: Y
authors.lastname: Habata
authors.forename: Yoshichika
authors.initials: Y
authors.lastname: Kobayashi
authors.forename: Toshiharu
authors.initials: T
authors.lastname: Shikanai
mesh_terms: D000595:Amino Acid Sequence; D002736:Chloroplasts / Q000201:enzymology / Q000235:genetics*; D017343:Genes, Plant; D005816:Genetic Complementation Test; D014644:Genetic Variation; D008969:Molecular Sequence Data; D009252:NADPH Dehydrogenase / Q000235:genetics* / Q000378:metabolism; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics*; D017393:RNA Editing; D016601:RNA-Binding Proteins / Q000737:chemistry / Q000235:genetics*; D013045:Species Specificity; D014026:Nicotiana / Q000201:enzymology / Q000235:genetics*
chemical_list: D010940:Plant Proteins; D016601:RNA-Binding Proteins; D009252:NADPH Dehydrogenase