Pinon R, Leney E
Nucleic Acids Res. 1975 Jul;2(7):1023-42. doi: 10.1093/nar/2.7.1023.
Two new endonuclease activities, endonuclease B and endonuclease C, obtained from yeast nuclear preparations have been separated and partially characterized. Endonuclease B has a primary requirement for Mn2+ which cannot be replaced by Mg2+ or Ca2+, and makes single-strand scissions in double-stranded DNA. Endonculease C is activated by either Mn2+ or Mg2+, and makes single-strand scissions with Mg2+, while with Mn2+, scissions are made which result in double-strand breaks. Neither enzyme is active on denatured DNA, and both are inhibited by yeast RNA. Both enzymes exhibit pH optima at pH 5.0 and PH 7.2, and leave 5'-phosphoryl termini.
从酵母核提取物中获得的两种新的核酸内切酶活性,即核酸内切酶B和核酸内切酶C,已被分离并进行了部分特性鉴定。核酸内切酶B主要需要Mn2+,Mg2+或Ca2+不能替代它,它能在双链DNA中产生单链切口。核酸内切酶C可被Mn2+或Mg2+激活,在有Mg2+时产生单链切口,而在有Mn2+时产生导致双链断裂的切口。这两种酶对变性DNA均无活性,且都受到酵母RNA的抑制。两种酶在pH 5.0和pH 7.2时均表现出最适pH值,并留下5'-磷酸末端。