The Second Chromophore in Drosophila Photolyase/Cryptochrome Family Photoreceptors
The Second Chromophore in Drosophila Photolyase/Cryptochrome Family Photoreceptors
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DOI：
10.1021/bi201536w
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发表时间：
2012-01-10
期刊：
影响因子：
2.9
通讯作者：
Sancar, Aziz
中科院分区：
文献类型：
--
作者：
Selby, Christopher P.;Sancar, Aziz
光裂合酶/隐花色素蛋白家族是含有FAD的黄素蛋白，其执行蓝光依赖性功能，包括DNA修复、植物生长和发育以及生物钟调节。除了FAD之外，该家族的许多成员还含有第二个发色团，其用作光天线，收集光并将激发能转移到FAD，从而提高系统的效率。第二个发色团是亚甲基四氢叶酸（MTHF）在大多数光解酶的特点，日期和FAD，FMN，或5-deazariboflavin在其他。迄今为止，在隐花色素中还没有发现第二个发色团。果蝇含有隐花色素/光裂合酶家族的三个成员：环丁烷嘧啶二聚体（CPD）光裂合酶、（6-4）光产物光裂合酶和隐花色素。我们开发了一个表达系统，能够将所有已知的第二生色团的同源隐花色素/光解酶家族成员。使用这个系统，我们表明，果蝇CPD光解酶和（6-4）光解酶雇用5-deazariboflavin作为其第二生色团，但果蝇隐花色素，这是进化更接近（6-4）比CPD光解酶的光解酶，缺乏第二生色团。
The photolyase/cryptochrome family of proteins are FAD-containing flavoproteins which carry out blue-light-dependent functions including DNA repair, plant growth and development, and regulation of the circadian clock. In addition to FAD, many members of the family contain a second chromophore which functions as a photoantenna, harvesting light and transferring the excitation energy to FAD and thus increasing the efficiency of the system. The second chromophore is methenyltetrahydrofolate (MTHF) in most photolyases characterized to date and FAD, FMN, or 5-deazariboflavin in others. To date, no second chromophore has been identified in cryptochromes. Drosophila contains three members of the cryptochrome/photolyase family: cyclobutane pyrimidine dimer (CPD) photolyase, (6-4) photoproduct photolyase, and cryptochrome. We developed an expression system capable of incorporating all known second chromophores into the cognate cryptochrome/photolyase family members. Using this system, we demonstrate that Drosophila CPD photolyase and (6-4) photolyase employ 5-deazariboflavin as their second chromophore, but Drosophila cryptochrome, which is evolutionarily closer to (6-4) photolyase than the CPD photolyase, lacks a second chromophore.