Boal Amie K, Yavin Eylon, Barton Jacqueline K
Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125, USA.
J Inorg Biochem. 2007 Nov;101(11-12):1913-21. doi: 10.1016/j.jinorgbio.2007.05.001. Epub 2007 May 17.
The [4Fe-4S] cluster is ubiquitous to a class of base excision repair enzymes in organisms ranging from bacteria to man and was first considered as a structural element, owing to its redox stability under physiological conditions. When studied bound to DNA, two of these repair proteins (MutY and Endonuclease III from Escherichia coli) display DNA-dependent reversible electron transfer with characteristics typical of high potential iron proteins. These results have inspired a reexamination of the role of the [4Fe-4S] cluster in this class of enzymes. Might the [4Fe-4S] cluster be used as a redox cofactor to search for damaged sites using DNA-mediated charge transport, a process well known to be highly sensitive to lesions and mismatched bases? Described here are experiments demonstrating the utility of DNA-mediated charge transport in characterizing these DNA-binding metalloproteins, as well as efforts to elucidate this new function for DNA as an electronic signaling medium among the proteins.
[4Fe-4S]簇在从细菌到人类的生物体中一类碱基切除修复酶中普遍存在，由于其在生理条件下的氧化还原稳定性，最初被认为是一种结构元件。当研究其与DNA结合时，其中两种修复蛋白（来自大肠杆菌的MutY和核酸内切酶III）表现出依赖于DNA的可逆电子转移，具有高电位铁蛋白的典型特征。这些结果促使人们重新审视[4Fe-4S]簇在这类酶中的作用。[4Fe-4S]簇是否可以用作氧化还原辅因子，通过DNA介导的电荷传输来寻找受损位点，而这一过程众所周知对损伤和错配碱基高度敏感？本文描述了一些实验，这些实验证明了DNA介导的电荷传输在表征这些DNA结合金属蛋白方面的效用，以及阐明DNA作为蛋白质间电子信号介质这一新功能的努力。
