Kim S T, Malhotra K, Smith C A, Taylor J S, Sancar A
Department of Biochemistry and Biophysics, University of North Carolina School of Medicine, Chapel Hill 27599.
Biochemistry. 1993 Jul 20;32(28):7065-8. doi: 10.1021/bi00079a001.
DNA photolyases catalyze the splitting of the cyclobutane ring joining the two dihydropyrimidines of a pyrimidine dimer by a photoinduced electron-transfer reaction. Previous studies concluded that photolyase repairs only the cis-syn form of the eight stereoisomers of the cyclobutane pyrimidine dimer (Pyr[ ]Pyr). In this study we found that Escherichia coli photolyase binds to the trans-syn-I isomer of T[ ]T with about 10(4)-fold lower affinity than the cis-syn isomer but it repairs it relatively efficiently.
DNA光解酶通过光诱导电子转移反应催化连接嘧啶二聚体两个二氢嘧啶的环丁烷环的裂解。先前的研究得出结论，光解酶仅修复环丁烷嘧啶二聚体（Pyr[ ]Pyr）的八种立体异构体中的顺式-顺式形式。在本研究中，我们发现大肠杆菌光解酶与T[ ]T的反式-顺式-I异构体结合，其亲和力比顺式-顺式异构体低约10^4倍，但它能相对有效地修复该异构体。
