An endonuclease from Escherichia coli that introduces single polynucleotide chain scissions in ultraviolet-irradiated DNA

J Biol Chem. 1976 Mar 10;251(5):1438-45.

Abstract

An endonuclease that makes single polynucleotide chain scissions in ultraviolet-irradiated DNA has been purified from Escherichia coli. The activity has the following properties: (a) unirradiated DNA is attacked very little if at all; (b) single strand DNA is not attacked, whether irradiated or not; (c) there is no requirement for divalent cations and the activity is not affected by the addition of EDTA; (d) the pH optimum is approximately 7; (e) the activity is inhibited by 1 M NaCl, single strand DNA, transfer RNA and double strand DNA; (f) the sedimentation coefficient, S20,w, is approximately 2.6; (g) it is a basic protein. The enzyme is tentatively named E. coli endonuclease III. The physiological function of the endonuclease has not yet been established.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Coliphages
  • DNA, Circular
  • DNA, Single-Stranded
  • Deoxyribonucleases / isolation & purification
  • Deoxyribonucleases / metabolism*
  • Endonucleases / isolation & purification
  • Endonucleases / metabolism*
  • Escherichia coli / enzymology*
  • Hydrogen-Ion Concentration
  • Kinetics
  • Osmolar Concentration
  • Radiation Effects

Substances

  • DNA, Circular
  • DNA, Single-Stranded
  • Deoxyribonucleases
  • Endonucleases