A novel oligoribonuclease of Escherichia coli. I. Isolation and properties

Niyogi, S. K. ; Datta, A. K. (1975) A novel oligoribonuclease of Escherichia coli. I. Isolation and properties Journal of Biological Chemistry, 250 (18). pp. 7307-7312. ISSN 0021-9258

PDF - Publisher Version

Official URL: http://www.jbc.org/content/250/18/7307.abstract


A new ribonuclease has been isolated from Escherichia coli. The enzyme is present in the 100,000 times g supernatant fraction and has been purified over 200-fold. Studies of the enzyme reveal that: 1. The enzyme shows a marked preference for oligoribonucleotides; indeed, the reaction rate is inversely proportional to the chain length of the substrate. The enzyme does not attack polynucleotides even at high concentrations of enzyme and has no detectable DNase activity. 2. The enzyme is stimulated strongly by Mn2+, less strongly by Mg2+, and not at all by Ca2+ and monovalent cations. 3. The enzyme is purified free of RNase I, RNase II, RNase III, polynucleotide phosphorylase, and other known ribonucleases of E. coli. The enzyme displays identical properties when isolated from mutants of E. coli that are deficient in the above ribonucleases. 4. The enzyme has a marked thermostability, a point of further distinction from RNase II.

Item Type:Article
Source:Copyright of this article belongs to The American Society for Biochemistry and Molecular Biology.
ID Code:9079
Deposited On:29 Oct 2010 11:42
Last Modified:16 May 2016 18:56

Repository Staff Only: item control page