title: Self-splicing activity of the mitochondrial group-I introns from Aspergillus nidulans and related introns from other species.
abstract: The mitochondrial genome of Aspergillus nidulans contains several group-I introns. Each one has been assayed for its ability to self-splice in vitro in the absence of proteins. The intron from the apocytochrome b gene is unusual among subgroup IB4 introns in being able to self-splice, unlike a similar intron from Saccharomyces cerevisiae. The first intron in the cytochrome oxidase subunit-1 gene self-splices but only correctly completes the first step of splicing; cryptic 3' splice-sites are recognized instead and these are also used at a low frequency in vivo. The highly homologous intron from Podospora anserina completes both steps in vitro. The remaining introns do not self-splice. The correlation between subgroup category, the likely presence of specific tertiary interactions, and self-splicing activity is discussed.
authors.affiliation: Department of Biology, Temple University, Philadelphia, PA 19122, USA.
authors.forename: M
authors.initials: M
authors.lastname: Hur
authors.forename: W J
authors.initials: WJ
authors.lastname: Geese
authors.forename: R B
authors.initials: RB
authors.lastname: Waring
mesh_terms: D001059:Apoproteins / Q000235:genetics; D001203:Ascomycota / Q000235:genetics; D001233:Aspergillus nidulans / Q000235:genetics*; D001483:Base Sequence; D003573:Cytochrome b Group / Q000235:genetics; D045303:Cytochromes b; D004271:DNA, Fungal / Q000235:genetics; D004272:DNA, Mitochondrial / Q000235:genetics*; D003576:Electron Transport Complex IV / Q000235:genetics; D007438:Introns / Q000235:genetics*; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D012326:RNA Splicing / Q000235:genetics*; D012331:RNA, Fungal / Q000737:chemistry / Q000235:genetics*; D012441:Saccharomyces cerevisiae / Q000235:genetics
chemical_list: D001059:Apoproteins; D003573:Cytochrome b Group; D004271:DNA, Fungal; D004272:DNA, Mitochondrial; D012331:RNA, Fungal; D045303:Cytochromes b; D003576:Electron Transport Complex IV