The archaeal cofactor F0 is a light-harvesting antenna chromophore in eukaryotes
The archaeal cofactor F0 is a light-harvesting antenna chromophore in eukaryotes
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DOI：
10.1073/pnas.0812665106
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发表时间：
2009-07-14
影响因子：
11.1
通讯作者：
Carell, Thomas
中科院分区：
文献类型：
--
作者：
Glas, Andreas F.;Maul, Melanie J.;Carell, Thomas
古细菌具有独特的生化系统，与真核生物和真细菌的生化途径截然不同。7,8-二甲基-8-羟基-5去氮黄素（F-0）和F-420是独特的含去氮黄素辅酶和产甲烷特征分子，在与甲烷生物合成和光依赖性DNA修复相关的各种生化转化中必不可少。去氮黄素辅助因子系统在甲烷生物合成过程中作为低电位氢化物穿梭体F-420/F420H2发挥作用。在DNA光解酶修复蛋白中，去氮黄素辅因子作为光收集能量传递色素处于去质子化状态。因此，它将蓝色阳光转化为蛋白质所使用的能量，以驱动基本的修复过程。对黑腹果蝇（Drosophila melanogaster）真核生物（6-4）DNA光解酶的分析发现了一个紧密结合F-0的结合袋。口袋中的残基通过去质子化激活辅因子，从而开启光吸收和能量转移。F-0与D. melanogaster蛋白复合物的晶体结构显示了F-0结合和活化的原子细节，从而可以表征参与F-0活化的残基。结果表明，迄今为止被认为严格限于古生物王国的F-0/F-420辅酶系统的分布远比预期的广泛。从原始真核生物牛油Ostreococcus tauri提取的D. melanogaster提取物和DNA光解酶的分析提供了F-0辅助因子存在于高等真核生物中的直接证据。
Archae possess unique biochemical systems quite distinct from the pathways present in eukaryotes and eubacteria. 7,8-Dimethyl-8-hydroxy-5deazaflavin (F-0) and F-420 are unique deazaflavin-containing coenzyme and methanogenic signature molecules, essential for a variety of biochemical transformations associated with methane biosynthesis and light-dependent DNA repair. The deazaflavin cofactor system functions during methane biosynthesis as a low-potential hydrid shuttle F-420/F420H2. In DNA photolyase repair proteins, the deazaflavin cofactor is in the deprotonated state active as a light-collecting energy transfer pigment. As such, it converts blue sunlight into energy used by the proteins to drive an essential repair process. Analysis of a eukaryotic (6-4) DNA photolyase from Drosophila melanogaster revealed a binding pocket, which tightly binds F-0. Residues in the pocket activate the cofactor by deprotonation so that light absorption and energy transfer are switched on. The crystal structure of F-0 in complex with the D. melanogaster protein shows the atomic details of F-0 binding and activation, allowing characterization of the residues involved in F-0 activation. The results show that the F-0/F-420 coenzyme system, so far believed to be strictly limited to the archael kingdom of life, is far more widespread than anticipated. Analysis of a D. melanogaster extract and of a DNA photolyase from the primitive eukaryote Ostreococcus tauri provided direct proof for the presence of the F-0 cofactor also in higher eukaryotes.