Takahashi M, Negishi K, Hayatsu H
Biochem Biophys Res Commun. 1987 Feb 27;143(1):104-9. doi: 10.1016/0006-291x(87)90636-x.
N4-Aminodeoxycytidine triphosphate, a putative metabolite of N4-aminocytidine which is a potent mutagen, is incorporated, in vitro, into polynucleotides in place of dCTP and at a much lesser extent, but significantly, in place of dTTP by E. coli DNA polymerase I large fragment. The activity of the polymerase to proofread this unnatural nucleotide has now been investigated. The results indicate that the 3'-5' exonuclease in the polymerase recognizes N4-aminocytosine as an incorrect base when N4-aminocytosine is incorporated opposite adenine but the enzyme cannot distinguish N4-aminocytosine from cytosine when it is incorporated opposite guanine.
N4-氨基脱氧胞苷三磷酸是一种潜在的诱变剂N4-氨基胞苷的代谢产物，在体外可被大肠杆菌DNA聚合酶I大片段替代dCTP掺入多核苷酸中，并且在程度上小得多但显著地替代dTTP掺入。现在已经研究了该聚合酶校对这种非天然核苷酸的活性。结果表明，当N4-氨基胞嘧啶与腺嘌呤配对掺入时，聚合酶中的3'-5'核酸外切酶将N4-氨基胞嘧啶识别为错误碱基，但当它与鸟嘌呤配对掺入时，该酶无法将N4-氨基胞嘧啶与胞嘧啶区分开来。
