Editing of the grapevine mitochondrial cytochrome b mRNA and molecular modeling of the protein.
Cytochrome b (COB), the central catalytic subunit of ubiquinol cytochrome c reductase, is a component of the transmembrane electron transfer chain that generates proton motive force. Some plant COB mRNAs are processed by RNA editing, which changes the gene coding sequence. This report presents the sequences of the grapevine (Vitis vinifera L.) mitochondrial gene for apocytochrome b (cob), the edited mRNA and the deduced protein. Grapevine COB is 393 amino acids long and is 98% identical to homologs in rapeseed, Arabidopsis thaliana and Oenothera sp. Twenty-one C-U editing sites were identified in the grapevine cob mRNA, resulting in 20 amino acid changes. These changes increase the overall hydrophobicity of the protein and result in a more conserved protein. Molecular modeling of grapevine COB shows that residues changed by RNA editing fit the secondary structure characteristic of an integral membrane protein. This is the first complete mitochondrial gene reported for grapevine. Novel RNA editing sites were identified in grapevine cob, which have not been previously reported for other plants.
Islas-Osuna
María A
MA
Dirección de Tecnología de Alimentos de Origen Vegetal, Centro de Investigación en Alimentación y Desarrollo, A.C. Apdo. Postal 1735, Hermosillo, Sonora 83000, México. islasosu@cascabel.ciad.mx
Silva-Moreno
Begonia
B
Caceres-Carrizosa
Nidia
N
García-Robles
Jesús M
JM
Sotelo-Mundo
Rogerio R
RR
Yepiz-Plascencia
Gloria M
GM
D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D001483:Base Sequence; D003198:Computer Simulation; D045303:Cytochromes b / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D024101:Mitochondrial Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010944:Plants / Q000235:genetics*; D011487:Protein Conformation; D017393:RNA Editing; D012333:RNA, Messenger / Q000235:genetics* / Q000378:metabolism; D000077278:RNA, Mitochondrial; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid; D014158:Transcription, Genetic / Q000235:genetics; D027843:Vitis / Q000235:genetics*
D024101:Mitochondrial Proteins; D012333:RNA, Messenger; D000077278:RNA, Mitochondrial; C029305:mitochondrial messenger RNA; D045303:Cytochromes b