Ribosomal protein L10 is encoded in the mitochondrial genome of many land plants and green algae.
BACKGROUND
The mitochondrial genomes of plants generally encode 30-40 identified protein-coding genes and a large number of lineage-specific ORFs. The lack of wide conservation for most ORFs suggests they are unlikely to be functional. However, an ORF, termed orf-bryo1, was recently found to be conserved among bryophytes suggesting that it might indeed encode a functional mitochondrial protein.


RESULTS
From a broad survey of land plants, we have found that the orf-bryo1 gene is also conserved in the mitochondria of vascular plants and charophycean green algae. This gene is actively transcribed and RNA edited in many flowering plants. Comparative sequence analysis and distribution of editing suggests that it encodes ribosomal protein L10 of the large subunit of the ribosome. In several lineages, such as crucifers and grasses, where the rpl10 gene has been lost from the mitochondrion, we suggest that a copy of the nucleus-encoded chloroplast-derived rpl10 gene may serve as a functional replacement.


CONCLUSIONS
Despite the fact that there are now over 20 mitochondrial genome sequences for land plants and green algae, this gene has remained unidentified and largely undetected until now because of the unlikely coincidence that most of the earlier sequences were from the few lineages that lack the intact gene. These results illustrate the power of comparative sequencing to identify novel genomic features.
Mower
Jeffrey P
JP
Department of Agronomy and Horticulture, University of Nebraska, Center for Plant Science Innovation, Lincoln, NE, USA. jmower2@unl.edu
Bonen
Linda
L
D000595:Amino Acid Sequence; D000460:Chlorophyta / Q000235:genetics*; D055028:Comparative Genomic Hybridization; D017124:Conserved Sequence; D048028:DNA, Algal / Q000235:genetics; D018744:DNA, Plant / Q000235:genetics; D019143:Evolution, Molecular; D054629:Genome, Mitochondrial; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D016366:Open Reading Frames; D010944:Plants / Q000235:genetics*; D000080882:Ribosomal Protein L10; D012269:Ribosomal Proteins / Q000235:genetics*; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA
D048028:DNA, Algal; D018744:DNA, Plant; D012269:Ribosomal Proteins