Youil R, Kemper B W, Cotton R G
Olive Miller Laboratory, Murdoch Institute, Royal Children's Hospital, Parkville, Victoria, Australia.
Proc Natl Acad Sci U S A. 1995 Jan 3;92(1):87-91. doi: 10.1073/pnas.92.1.87.
Each of four possible sets of mismatches (G.A/C.T, C.C/G.G, A.A/T.T, and C.A/G.T) containing the 8 possible single-base-pair mismatches derived from isolated mutations were examined to test the ability of T4 endonuclease VII to consistently detect mismatches in heteroduplexes. At least two examples of each set of mismatches were studied for cleavage in the complementary pairs of heteroduplexes formed between normal and mutant DNA. Four deletion mutations were also included in this study. The various PCR-derived products used in the formation of heteroduplexes ranged from 133 to 1502 bp. At least one example of each set showed cleavage of at least one strand containing a mismatch. Cleavage of at least one strand of the pairs of heteroduplexes occurred in 17 of the 18 known single-base-pair mutations tested, with an A.A/T.T set not being cleaved in any mismatched strand. We propose that this method may be effective in detecting and positioning almost all mutational changes when DNA is screened for mutations.
对从分离的突变中衍生出的8种可能的单碱基对错配所构成的四种可能的错配组合（G.A/C.T、C.C/G.G、A.A/T.T和C.A/G.T）分别进行了检测，以测试T4核酸内切酶VII在异源双链体中持续检测错配的能力。针对正常DNA与突变DNA形成的异源双链体互补对中的切割情况，对每组错配至少研究了两个实例。本研究还纳入了四个缺失突变。用于形成异源双链体的各种PCR衍生产物长度在133至1502 bp之间。每组中至少有一个实例显示含有错配的至少一条链发生了切割。在测试的18个已知单碱基对突变中，有17个的异源双链体对中至少有一条链发生了切割，而A.A/T.T组合的任何错配链均未被切割。我们认为，当筛选DNA中的突变时，该方法可能在检测和定位几乎所有突变变化方面有效。
