Identification of a group-I intron within the 25S rDNA from the yeast Arxula adeninivorans

The 25S rDNA of the yeast Arxula adeninivorans LS3 has been closed from a genomic library and sequenced. This DNA could be localized on chromosome 1 from A. adeninivorans and comprised 3790 bp. The DNA sequence from this rDNA of the strain LS3 is very similar to the 25S rDNA of Candida albicans (91.7%), Saccharomyces cerevisiae (90.5%), Schizosaccharomyces pombe (83.8%) and Mucor racemosus (79.2%). Additionally a 411 bp insertion could be localized within the 25S rDNA. This intervening sequence, which is devoid of any long open reading frame, is a group-IC intron as revealed from its site of insertion, predicted secondary structure, and its self-splicing capability. The Arxula intron is intermediate in structure and sequence between the ribosomal introns of Tetrahymena thermophila and C. albicans.