期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1990
卷号：87
期号：2
页码：548-552
DOI：10.1073/pnas.87.2.548
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：We have determined from nucleotide sequence analysis that the subterminal and terminal exons of a respiratory chain NADH dehydrogenase subunit I gene in broad bean mitochondrial DNA (mtDNA) are separated by a group II intron. Within this intron is a 687-codon open reading frame that, from considerations of similarity between amino acid sequences predicted from this open reading frame and maturase-coding sequences in group II introns of certain fungal mitochondrial genes, appears to encode a maturase-related protein. Transcripts complementary to this broad bean sequence (designated a mat-r gene) were detected among RNAs isolated from broad bean mitochondria. Data obtained from DNA-DNA hybridizations indicated that soybean and corn mtDNAs also contain a mat-r gene and suggested that only one copy of this gene occurs in each plant mtDNA. The putative protein specified by the broad bean mat-r gene contains amino acid sequences characteristic of reverse transcriptases. Because of this, consideration is given to the possibility that the maturase-related protein may be functional in the mechanisms by which plant mtDNA sequences are rearranged and foreign sequences are incorporated into plant mtDNAs.
