Catalytic site components common to both splicing steps of a group II intron.
The splicing of group II introns occurs in two steps involving substrates with different chemical configurations. The question of whether these two steps are catalyzed by a single or two separate active sites is a matter of debate. Here, certain bases and phosphate oxygen atoms at conserved positions in domain V of a group II self-splicing intron are shown to be required for catalysis of both splicing steps. These results show that the active sites catalyzing the two steps must, at least, share common components, ruling out the existence of two completely distinct active sites in group II introns.
Unité de Génétique Moléculaire des Levures, URA 1149 du CNRS, Département de Biologie Moléculaire, Institut Pasteur, Paris, France.
G
G
Chanfreau
A
A
Jacquier
D001483:Base Sequence; D001665:Binding Sites; D002384:Catalysis; D003576:Electron Transport Complex IV / Q000235:genetics; D004591:Electrophoresis, Polyacrylamide Gel; D005091:Exons; D007438:Introns; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D012326:RNA Splicing; D012331:RNA, Fungal / Q000737:chemistry / Q000235:genetics*; D012441:Saccharomyces cerevisiae / Q000201:enzymology / Q000235:genetics; D013873:Thionucleotides / Q000235:genetics
D012331:RNA, Fungal; D013873:Thionucleotides; D003576:Electron Transport Complex IV