[Editing of the mitochondrial cox3 transcript may yield a new site of protein-protein interactions in wild cereal Elymus sibiricus L]. / Redaktirovanie transkripta gena cox3 v mitokhondriiakh dikorastushchego zlaka Elumus sibiricus L. mozhet privodit' k obrazovaniiu novogo uchastka belok-belkovogo vzaimodeistviia.

With PCR, RT-PCR, and direct sequencing, complete nucleotide sequences were established for the Elymus sibiricus mitochondrial cytochrome c oxidase subunit 3 gene (cox3) and its cDNA. The cox3 transcript was shown to have 12 editing sites with changes affecting the amino acid sequence of the protein product. The editing of the primary cox3 transcript was found to change the position of a site of protein-protein interactions. The results demonstrate again the important role of mRNA editing in posttranscriptional regulation of the expression of plant mitochondrial genes.

[Reconstruction of the phylogenetic position of larch (Larix sukaczewii Dylis) by sequencing data for the trnK intron of chloroplast DNA]. / Rekonstruktsiia sistematicheskogo polozheniia listvennitsy sukacheva (Larix sukaczewii Dylis) po dannym sekvenirovaniia trnK introna khloroplastnoi DNK.

To reconstruct the systematic relationships of larch Larix sukaczewii, we used the chloroplast trnK intron sequences of L. decidua, L. sukaczewii, L. sibirica, L. czekanovskii, and L. gmelinii. Analysis of phylogenetic trees constructed using the maximum parsimony and maximum likelihood methods showed a clear divergence of the trnK intron sequences between L. sukaczewii and L. sibirica. This divergence reaches intraspecific level, which supports a previously published hypothesis on the taxonomic isolation of L. sukaczewii.

Identification of highly conserved hydrophobic amino acid motif in deduced amino acid sequence of Elymus sibiricus L. mitochondrial S13 ribosomal protein.

The nucleotide sequence of mitochondrial ribosomal protein rps13 gene from wild perennial grass Elymus sibiricus is presented. It was determined by the method of PCR amplification with specific oligonucleotide primers and the direct sequencing of the amplification product. The sequence of E. sibiricus mitochondrial gene for S13 predicts a hydrophobic ribosomal protein of 116 amino acids that shows strong similarity to those of wheat (99.7% identity) and maize (98%). The deduced amino acid sequence of S13 protein from E. sibiricus and homologous plant's (Zea mays, Daucus carota, Nicotiana tabacum, Marchantia polymorpha) and nonplant's (Escherichia coli) proteins shows the presence of hydrophobic amino acids' motif -L-X10-L-X10-M-X10-L-X10-L-. Slightly modified it can be found in many other ribosomal proteins. This conserved motif is presumed to be particularly important for association of the ribosomal S13 protein with other proteins in the small subunit of the mitochondrial ribosome.