Structural specificity of Rn nuclease I as probed on yeast tRNA(Phe) and tRNA(Asp).
A single-strand-specific nuclease from rye germ (Rn nuclease I) was characterized as a tool for secondary and tertiary structure investigation of RNAs. To test the procedure, yeast tRNA(Phe) and tRNA(Asp) for which the tertiary structures are known, as well as the 3'-half of tRNA(Asp) were used as substrates. In tRNA(Phe) the nuclease introduced main primary cuts at positions U33 and A35 of the anticodon loop and G18 and G19 of the D loop. No primary cuts were observed within the double stranded stems. In tRNA(Asp) the main cuts occurred at positions U33, G34, U35, C36 of the anticodon loop and G18 and C20:1 positions in the D loop. No cuts were observed in the T loop in intact tRNA(Asp) but strong primary cleavages occurred at positions psi 55, C56, A57 within that loop in the absence of the tertiary interactions between T and D loops (use of 3'-half tRNA(Asp)). These results show that Rn nuclease I is specific for exposed single-stranded regions.
Przykorska
A
A
Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warszawa.
el Adlouni
C
C
Keith
G
G
Szarkowski
J W
JW
Dirheimer
G
G
D001482:Base Composition; D001483:Base Sequence; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D012349:RNA, Transfer, Asp / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D012360:RNA, Transfer, Phe / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D012259:Ribonuclease, Pancreatic / Q000378:metabolism*; D012434:Secale; D013379:Substrate Specificity; D015003:Yeasts / Q000235:genetics
D012349:RNA, Transfer, Asp; D012360:RNA, Transfer, Phe; D012259:Ribonuclease, Pancreatic