Amino acids and peptides. LVII. Synthetic peptide with a sequence of ribonuclease from Sulfolobus solfataricus, SSR(1-62), does not function as an RNase.
The 62 residue peptide, SSR(1-62), whose sequence corresponds to that of ribonuclease (RNase) from Sulfolobus solfataricus, and its related peptides, SSR(1-22) and SSR(10-62), were chemically synthesized and their RNase activity and DNA-binding activity were examined. The RNase activity assay using yeast RNA or tRNA(fMet) as substrate showed that the synthetic peptide SSR(1-62) did not hydrolyze yeast RNA or tRNA(fMet). These data were not consistent with previous reports that both the native peptide isolated from S. solfataricus [Fusi et al. (1993) Eur. J. Biochem. 211, 305-311] and the recombinant peptide expressed in Escherichia coli [Fusi et al. (1995) Gene 154, 99-103] were able to hydrolyze tRNA(fMet). However, the synthetic SSR(1-62) exhibited DNA-binding activity. In the presence of synthetic SSR(1-62), the cleavage of DNA (plasmid pUCRh2-4) by restriction endonuclease (EcoRI) was not observed, suggesting that synthetic SSR(1-62) bound to DNA protected DNA from its enzymatic digestion. Neither SSR(1-22) nor SSR(10-62) prevented DNA from being cleaved by a restriction enzyme. These findings strongly suggest the importance of not only the N-terminal region of SSR(1-62) but also the C-terminal region for DNA-binding. Circular dichroism spectroscopy of synthetic SSR(1-62) indicated a beta-sheet conformation, in contrast with synthetic SSR(1-22), which exhibited an unordered conformation.
Joshi
S
S
STAR Biochemicals, Torrance, CA, USA.
Tsuda
Y
Y
Shintomi
N
N
Kondo
H
H
Nishiyama
Y
Y
Iwama
M
M
Ohgi
K
K
Irie
M
M
Okada
Y
Y
D000595:Amino Acid Sequence; D000596:Amino Acids / Q000378:metabolism*; D019843:Archaeal Proteins / Q000138:chemical synthesis / Q000378:metabolism*; D002942:Circular Dichroism; D004247:DNA / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000138:chemical synthesis / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D006868:Hydrolysis; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000138:chemical synthesis / Q000378:metabolism*; D011487:Protein Conformation; D012313:RNA / Q000378:metabolism; D012358:RNA, Transfer, Met / Q000378:metabolism; D012260:Ribonucleases / Q000138:chemical synthesis / Q000378:metabolism*; D017421:Sequence Analysis; D016944:Sulfolobus / Q000201:enzymology*
D000596:Amino Acids; D019843:Archaeal Proteins; D004268:DNA-Binding Proteins; D010446:Peptide Fragments; D012358:RNA, Transfer, Met; D012313:RNA; D004247:DNA; D012260:Ribonucleases