Adrenal Cortical Ribonuclease H (Hybrid) 1

Abstract

Summary

Ribonuclease Hybrid (RNase H) from adrenal cortical tissue has been characterized. RNase H specifically degrades the RNA strand of purified RNA:DNA hybrids but is inactive on single- or double-stranded RNA or on DNA. The mode of cleavage by RNase H is endonucleolytic, producing oligoribonucleotides with 3′-hydroxyl and 5′-phosphate termini. ACTH administration to guinea pigs results in no detectable change in adrenal cortical RNase H activity at times when changes in DNA synthesis are marked.

We are grateful to Drs. Peter H. Williams and Donald R. Helinski for the collaboration in the experiments involving col E₁ DNA.