title: Targeting presequence acquisition after mitochondrial gene transfer to the nucleus occurs by duplication of existing targeting signals.
abstract: We have cloned a gene for mitochondrial ribosomal protein S11 (RPS11), which is encoded in lower plants by the mitochondrial genome, in higher plants by the nuclear genome, demonstrating genetic information transfer from the mitochondrial genome to the nucleus during flowering plant evolution. The sequence s11-1 encodes an N-terminal extension as well as an organelle-derived RPS11 region. Surprisingly, the N-terminal region has high amino acid sequence similarity with the presequence of the beta-subunit of ATP synthase from plant mitochondria, suggesting a common lineage of the presequences. The deduced N-terminal region of s11-2, a second nuclear-encoded homolog of rps11, shows high sequence similarity with the putative presequence of cytochrome oxidase subunit Vb. The sharing of the N-terminal region together with its 5' flanking untranslated nucleotide sequence in different proteins strongly suggests an involvement of duplication/recombination for targeting signal acquisition after gene migration. A remnant of ancestral rps11 sequence, transcribed and subjected to RNA editing, is found in the mitochondrial genome, indicating that inactivation of mitochondrial rps11 gene expression was initiated at the translational level prior to termination of transcription.
authors.affiliation: National Institute of Agrobiological Resources, Department of Molecular Biology, Tsukuba, Ibaraki, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Kadowaki
authors.forename: N
authors.initials: N
authors.lastname: Kubo
authors.forename: K
authors.initials: K
authors.lastname: Ozawa
authors.forename: A
authors.initials: A
authors.lastname: Hirai
mesh_terms: D000251:Adenosine Triphosphatases / Q000737:chemistry / Q000235:genetics*; D000595:Amino Acid Sequence; D001483:Base Sequence; D005075:Biological Evolution; D002467:Cell Nucleus / Q000378:metabolism*; D017124:Conserved Sequence; D004272:DNA, Mitochondrial / Q000235:genetics*; D003576:Electron Transport Complex IV / Q000737:chemistry / Q000235:genetics*; D004792:Enzyme Precursors / Q000737:chemistry / Q000235:genetics*; D015723:Gene Library; D008928:Mitochondria / Q000378:metabolism*; D008969:Molecular Sequence Data; D012275:Oryza / Q000378:metabolism; D010944:Plants / Q000235:genetics / Q000378:metabolism*; D015183:Restriction Mapping; D012269:Ribosomal Proteins / Q000235:genetics* / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid
chemical_list: D004272:DNA, Mitochondrial; D004792:Enzyme Precursors; D012269:Ribosomal Proteins; C045454:ribosomal protein S11; D003576:Electron Transport Complex IV; D000251:Adenosine Triphosphatases