title: Degradation by the 2',5'-phosphodiesterase activity of mouse cells requires the presence of a ribo hydroxyl group in the penultimate position of the oligonucleotide substrate.
abstract: A series of 9-beta-D-xylofuranosyladenine (xyloA or xyloadenosine) substituted analogs of 2-5A core trimer and tetramer were examined for their ability to be degraded by the 2',5'-phosphodiesterase activity of cytoplasmic extracts of mouse L cells. Two distinct groups of xyloA-substituted analogs could be readily discriminated. The first group contained xyloadenosine at the 2'-termini and included A2'p5'A2'p5'(xyloA) and A2'p5'A2'p5'A2'p5'(xyloA). These oligomers behaved as did their parent oligoadenylates in that they were equally sensitive to degradation by the 2',5'-phosphodiesterase activity. The second group of oligonucleotides bore a xyloadenosine residue in the penultimate nucleotide residues of the oligomers and included A2'p5'(xyloA)2'p5'(xyloA), (xyloA)2'p5'(xyloA)2'p5'(xyloA), A2'p5'A2'p5'(xyloA)2'p5'(xyloA) and (xyloA)2'p5' (xyloA)2'p5'(xyloA)2'p5'(xyloA). This group was quite resistant to 2',5'-phosphodiesterase activity. In all, the findings demonstrate that the ribo configuration 3'-hydroxyl group in the penultimate nucleotide of the oligonucleotide substrate is a prerequisite for the 2',5'-phosphodiesterase activity.
mesh_terms: D000227:Adenine Nucleotides; D000818:Animals; D005095:Exoribonucleases / Q000378:metabolism*; D007700:Kinetics; D007739:L Cells / Q000201:enzymology; D051379:Mice; D009843:Oligoribonucleotides; D013379:Substrate Specificity
chemical_list: D000227:Adenine Nucleotides; D009843:Oligoribonucleotides; C023505:2',5'-oligoadenylate; D005095:Exoribonucleases; C029364:2'-phosphodiesterase