Critical sequences within mitochondrial introns: cis-dominant mutations of the "cytochrome-b-like" intron of the oxidase gene.
We have established the DNA sequence of two cis-dominant mutations located in the fourth intron, a14, of the yeast mitochondrial gene oxi3. These mutations prevent the synthesis of subunit I of cytochrome oxidase. Both mutations affect a very short DNA sequence located several hundred base pairs from the intron-exon junctions. An identical sequence is found in the cob-box gene; and this sequence is critical for the excision of the cytochrome b intron. Our interpretation is that this short sequence represents a common signal that must be recognized by the box7-encoded mRNA maturase, in conjunction with the mitochondrial ribosome, to splice out the introns in the two nonhomologous genes, cob-box and oxi3.
D001483:Base Sequence; D003573:Cytochrome b Group; D003580:Cytochromes / Q000235:genetics; D004262:DNA Restriction Enzymes; D004272:DNA, Mitochondrial / Q000235:genetics*; D003576:Electron Transport Complex IV / Q000235:genetics*; D005786:Gene Expression Regulation; D009154:Mutation; D012326:RNA Splicing; D012335:RNA, Ribosomal / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics
D003573:Cytochrome b Group; D003580:Cytochromes; D004272:DNA, Mitochondrial; D012335:RNA, Ribosomal; D003576:Electron Transport Complex IV; D004262:DNA Restriction Enzymes