title: The preference of the mitochondrial endonuclease for a conserved sequence block in mitochondrial DNA is highly conserved during mammalian evolution.
abstract: Endonuclease activity identified in crude preparations of rat and human heart mitochondria has each been partially purified and characterized. Both the rat and human activities purify as a single enzyme that closely resembles the endonuclease of bovine-heart mitochondria (Cummings, O.W. et. al. (1987) J. Biol. Chem. 262:2005-2015). All three enzymes, for example elute similarly during gel filtration and DNA-cellulose chromatography, and exhibit similar enzymatic properties. Although the nucleotide sequences of the mtDNAs indicate that there has occurred an unusual degree of divergence in the displacement-loop region during mammalian evolution, the nucleotide specificities of the mt endonucleases appear highly conserved and show a striking preference for an evolutionarily-conserved sequence tract that is located upstream from the heavy (H)-strand origin of DNA replication (OriH).
authors.affiliation: Department of Pathology, Washington University School of Medicine, St Louis, MO 63110.
authors.forename: R L
authors.initials: RL
authors.lastname: Low
authors.forename: J M
authors.initials: JM
authors.lastname: Buzan
authors.forename: C L
authors.initials: CL
authors.lastname: Couper
mesh_terms: D000818:Animals; D001483:Base Sequence; D005075:Biological Evolution; D002846:Chromatography, Affinity; D002850:Chromatography, Gel; D004272:DNA, Mitochondrial / Q000378:metabolism*; D004277:DNA, Single-Stranded / Q000378:metabolism; D004706:Endodeoxyribonucleases / Q000378:metabolism*; D005796:Genes; D006801:Humans; D008929:Mitochondria, Heart / Q000201:enzymology*; D051381:Rats; D013329:Structure-Activity Relationship; D013379:Substrate Specificity
chemical_list: D004272:DNA, Mitochondrial; D004277:DNA, Single-Stranded; D004706:Endodeoxyribonucleases