Oligomeric compounds including
oligoribonucleotides and oligoribonucleosides are provided that have subsequences of 2′-pentoribofuranosyl nucleosides that activate dsRNase. The
oligoribonucleotides and oligoribonucleosides can include
substituent groups for increasing binding affinity to complementary
nucleic acid strand as well as
substituent groups for increasing
nuclease resistance. The oligomeric compounds are useful for diagnostics and other research purposes, for modulating the expression of a
protein in organisms, and for the diagnosis, detection and treatment of other conditions susceptible to
oligonucleotide therapeutics. Also included in the invention are mammalian ribonucleases, i.e., enzymes that degrade
RNA, and substrates for such ribonucleases. Such a
ribonuclease is referred to herein as a dsRNase, wherein “ds” indicates the RNase's specificity for certain double-stranded
RNA substrates. The artificial substrates for the dsRNases described herein are useful in preparing affinity matrices for purifying mammalian
ribonuclease as well as non-degradative
RNA-binding proteins.