Ra. Collins et Je. Olive, REVISION OF THE NUCLEOTIDE-SEQUENCE AND RNA SPLICING PATHWAY OF THE NEUROSPORA MITOCHONDRIAL GENE ENCODING ATPASE SUBUNIT-6, Current genetics, 25(6), 1994, pp. 514-518
Previous sequence analysis of the Neurospora oli2 (ATP6) mitochondrial
gene suggested that, in addition to a typical Group-I intron, it cont
ained an unusual, mostly-palindromic, 93-nucleotide intron. We report
hen revisions of the nucleotide sequence and analysis of the size and
sequence of reverse-transcriptase PCR products that show: (1) the Grou
p-I intron splice sites are located as predicted by previous DNA seque
nce analysis; (2) the putative 93-nt intron is not excised from the ma
ture mRNA, and most of this sequence is actually in the 5' untranslate
d region. We conclude that the Neurospora ATP6 gene contains only one
intron. Analysis of the cDNA sequence also confirms the non-universal
nature of the Neurospora mitochondrial genetic code: a TGA codon infer
red from the DNA sequence is present as UGA in the mRNA. This provides
direct evidence that this codon is not altered, for example by RNA ed
iting, to conform to the universal code.