Varlet I, Radman M, Brooks P
Institut Jacques Monod, Centre National de la Recherche Scientifique, Paris, France.
Proc Natl Acad Sci U S A. 1990 Oct;87(20):7883-7. doi: 10.1073/pnas.87.20.7883.
Repair of all 12 single base-pair mismatches by Xenopus egg extracts was measured by a physical assay with a sequence containing four overlapping restriction sites. The heteroduplex substrates, derivatives of M13 phage DNA, differed in sequence at the mismatch position only and permitted measurement of repair to both strands. The efficiency of repair varied about 4-fold between the most and least effectively repaired mismatches. Repair was most active with C/A and T/C mismatches but the efficiency varied depending on the orientation of the mismatch. Mismatch-specific DNA repair synthesis was also observed but the extent of repair was not always predictive of the extent of synthesis, suggesting the presence of different repair systems or different modes of mismatch recognition.
通过一种含有四个重叠限制酶切位点的序列的物理分析方法，测定了非洲爪蟾卵提取物对所有12种单碱基对错配的修复情况。异源双链底物是M13噬菌体DNA的衍生物，仅在错配位置的序列不同，并允许对两条链的修复进行测量。在修复效率最高和最低的错配之间，修复效率相差约4倍。C/A和T/C错配的修复最为活跃，但修复效率因错配的方向而异。还观察到错配特异性的DNA修复合成，但修复程度并不总是能预测合成程度，这表明存在不同的修复系统或错配识别的不同模式。
