An enzyme that breaks the internal phosphodiester bonds in a DNA molecule. Endonucleases of somatic tissue hydrolyze DNA by introducing double-strand breaks. Endonucleases isolated from cells in meiotic prophase produce single-strand breaks in the DNA with 5′ hydroxy termini. Single-strand breaks are essential first steps in replication and recombination. See Chronology, 1971, Howell and Stern; 1972, Hedgepeth, Goodman, and Boyer; restriction endonuclease.
Subjects: Medicine and Health — Genetics and Genomics.