Abstract: A method of inhibiting the self-splicing of a Group I intron is disclosed. The method uses an oligonucleotide having a sequence essentially identical to a guide sequence found in the 5? flanking exon and terminates with a 3? ribonucleoside. Usually the oligonucleotide has N3??P5? phosphoramidate or N3??P5? thiophiosphoramidate linkages rather than phosphodiester linkages. A method of inhibiting the growth of organisms having Group I intron, particularly certain pathogenic fungi including P. carinii, C. albicans, and A. nidulans using the oglionucleotide is also provided.

Abstract: Oligonucleotides that bind to and cause misfolding of functional RNA molecules are described. Also disclosed are the uses of the oligonucleotides to modify the function of such RNA molecules, to stabilize the RNA molecules in a misfolded conformation, to disrupt survivability of a pathogen or cancer cells (that require activity of the RNA molecule for survival) by disrupting the activity of the RNA molecules, treating or preventing pathogen infection in a patient, and treating a cancerous condition in a patient. Methods of designing the oligonucleotides of the present invention are also disclosed.