Dynamic interplays between three redox cofactors in a DNA photolyase revealed by spectral decomposition.
Dynamic interplays between three redox cofactors in a DNA photolyase revealed by spectral decomposition.
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通过光谱分解揭示 DNA 光裂合酶中三个氧化还原辅因子之间的动态相互作用。
DOI：
10.1016/j.xcrp.2023.101297
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发表时间：
2023
期刊：
影响因子：
--
通讯作者：
Yang,Xiaojing
中科院分区：
文献类型：
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作者：
Ren,Zhong;Kang,Weijia;Gunawardana,Semini;Bowatte,Kalinga;Thoulass,Katharina;Kaeser,Gero;Krauß,Norbert;Lamparter,Tilman;Yang,Xiaojing
光解酶催化的DNA修复是通过光依赖的电子转移事件完成的，从完全还原的黄素腺嘌呤二核苷酸到DNA损伤位点。前体DNA光裂合酶PhrB除了催化黄素外，还具有一个Ribolumazine辅因子和一个四铁四硫簇，但它们的功能作用知之甚少。在这里，我们采用时间分辨吸收光谱探测溶液和单晶PhrB的光诱导响应。我们共同分析了大量收集的光诱导的差异光谱从野生型和突变体PhrB在不同的光和氧化还原条件下获得。通过对159个时间序列进行奇异值分解，我们分析了光引起的光谱变化，并研究了三个辅因子之间的动态相互作用。我们的研究结果表明，这些辅因子形成了一个相互依赖的氧化还原网络，以协调光诱导的氧化还原反应。我们建议，ribolumazine辅因子作为一种光保护色素在强光或长时间照射下，而铁硫簇作为一个短暂的电子缓存，以保持平衡，否则两个独立的光反应的黄素和ribolumazine之间。
DNA repair catalyzed by photolyases is accomplished by a light-dependent electron transfer event from a fully reduced flavin adenine dinucleotide to a DNA lesion site. Prokaryotic DNA photolyase, PhrB, possesses a ribolumazine cofactor and a four-iron-four-sulfur cluster in addition to the catalytic flavin, but their functional roles are poorly understood. Here, we employ time-resolved absorption spectroscopy to probe light-induced responses in both solution and single crystals of PhrB. We jointly analyze a large collection of light-induced difference spectra from the wild-type and mutant PhrB obtained under different light and redox conditions. By applying singular value decomposition to 159 time series, we dissect light-induced spectral changes and examine the dynamic interplay between three cofactors. Our findings suggest that these cofactors form an interdependent redox network to coordinate light-induced redox responses. We propose that the ribolumazine cofactor serves as a photoprotective pigment under intense light or prolonged illumination, while the iron-sulfur cluster acts as a transient electron cache to maintain balance between two otherwise independent photoreactions of the flavin and ribolumazine.