Institute of Biosciences and Bioresources, National Research Council of Italy, Via P. Castellino 111, 80125 Naples, Italy.
DiSF-Dipartimento di Scienze del Farmaco, University of Piemonte Orientale 'A. Avogadro', Via Bovio 6, 28100 Novara, Italy.
Nucleic Acids Res. 2015 Oct 15;43(18):8801-16. doi: 10.1093/nar/gkv774. Epub 2015 Jul 30.
Alkylated DNA-protein alkyltransferases repair alkylated DNA bases, which are among the most common DNA lesions, and are evolutionary conserved, from prokaryotes to higher eukaryotes. The human ortholog, hAGT, is involved in resistance to alkylating chemotherapy drugs. We report here on the alkylated DNA-protein alkyltransferase, SsOGT, from an archaeal species living at high temperature, a condition that enhances the harmful effect of DNA alkylation. The exceptionally high stability of SsOGT gave us the unique opportunity to perform structural and biochemical analysis of a protein of this class in its post-reaction form. This analysis, along with those performed on SsOGT in its ligand-free and DNA-bound forms, provides insights in the structure-function relationships of the protein before, during and after DNA repair, suggesting a molecular basis for DNA recognition, catalytic activity and protein post-reaction fate, and giving hints on the mechanism of alkylation-induced inactivation of this class of proteins.
烷基化 DNA-蛋白质烷基转移酶修复烷基化 DNA 碱基，这些碱基是最常见的 DNA 损伤之一，在从原核生物到高等真核生物的进化过程中是保守的。人类同源物 hAGT 参与了对烷化化疗药物的耐药性。我们在这里报告了来自一种生活在高温下的古细菌物种的烷基化 DNA-蛋白质烷基转移酶 SsOGT，这种高温条件增强了 DNA 烷基化的有害影响。SsOGT 的异常高稳定性使我们有机会对该类蛋白质的反应后形式进行结构和生化分析。这项分析，以及对 SsOGT 在无配体和 DNA 结合形式下的分析，提供了在 DNA 修复之前、期间和之后蛋白质的结构-功能关系的见解，为 DNA 识别、催化活性和蛋白质反应后命运提供了分子基础，并提示了该类蛋白质因烷化诱导失活的机制。
