Preferential selection of adenosines for modification by double-stranded RNA adenosine deaminase.
Double-stranded RNA adenosine deaminase (dsRAD), previously called the double-stranded RNA (dsRNA) unwinding/modifying activity, modifies adenosines to inosines within dsRNA. We used ribonuclease U2 and a mutant of ribonuclease T1 to map the sites of modification in several RNA duplexes. We found that dsRAD had a 5' neighbor preference (A = U > C > G) but no apparent 3' neighbor preference. Further, the proximity of the strand termini affected whether an adenosine was modified. Most importantly, dsRAD exhibited selectivity, modifying a minimal number of adenosines in short dsRNAs. Our results suggest that the specific editing of glutamate receptor subunit B mRNA could be performed in vivo by dsRAD without the aid of specificity factors, and support the hypothesis that dsRAD is responsible for hypermutations in certain RNA viruses.
Polson
A G
AG
Howard Hughes Medical Institute, Department of Biochemistry, University of Utah, Salt Lake City 84132.
Bass
B L
BL
D000241:Adenosine / Q000378:metabolism*; D000243:Adenosine Deaminase / Q000378:metabolism*; D001483:Base Sequence; D003641:Deamination; D004722:Endoribonucleases / Q000378:metabolism; D007288:Inosine / Q000378:metabolism; D008969:Molecular Sequence Data; D009843:Oligoribonucleotides; D012313:RNA / Q000138:chemical synthesis / Q000378:metabolism; D017393:RNA Editing; D016601:RNA-Binding Proteins / Q000378:metabolism*; D017470:Receptors, Glutamate / Q000235:genetics / Q000378:metabolism; D006163:Ribonuclease T1 / Q000378:metabolism
D009843:Oligoribonucleotides; D016601:RNA-Binding Proteins; D017470:Receptors, Glutamate; D007288:Inosine; D012313:RNA; D004722:Endoribonucleases; D006163:Ribonuclease T1; C022544:ribonuclease U2; C000595356:ADAR protein, human; C567955:ADARB1 protein, human; D000243:Adenosine Deaminase; D000241:Adenosine