Restricted Degradation of U6 RNA in a Nuclear Extract of Ehrlich Ascites Tumor Cells

Abstract

A new nucleolytic activity that causes restricted digestion of U6 RNA was found in a nuclear extract of Ehrlich ascites tumor cells. This nucleolytic activity specifically degrades U6 RNA in the vicinity of its 3'-end with accumulation of a discrete sized degradation product of RNA of 90-95 nucleotides. Since this degradation product was not digested further by the nuclease under these conditions, this trimming of U6 RNA is supposed to be a biologically meaningful reaction. This nucleolytic activity required Mg²⁺, and was inhibited by Zn²⁺ or Ca²⁺.