Kanai S, Kikuno R, Toh H, Ryo H, Todo T
Department of Bioinfomatics, Biomolecular Engineering Research Institute, 6-2-3, Furuedai, Suita, Osaka, 565 Japan.
J Mol Evol. 1997 Nov;45(5):535-48. doi: 10.1007/pl00006258.
The photolyase-blue-light photoreceptor family is composed of cyclobutane pyrimidine dimer (CPD) photolyases, (6-4) photolyases, and blue-light photoreceptors. CPD photolyase and (6-4) photolyase are involved in photoreactivation for CPD and (6-4) photoproducts, respectively. CPD photolyase is classified into two subclasses, class I and II, based on amino acid sequence similarity. Blue-light photoreceptors are essential light detectors for the early development of plants. The amino acid sequence of the receptor is similar to those of the photolyases, although the receptor does not show the activity of photoreactivation. To investigate the functional divergence of the family, the amino acid sequences of the proteins were aligned. The alignment suggested that the recognition mechanisms of the cofactors and the substrate of class I CPD photolyases (class I photolyases) are different from those of class II CPD photolyases (class II photolyases). We reconstructed the phylogenetic trees based on the alignment by the NJ method and the ML method. The phylogenetic analysis suggested that the ancestral gene of the family had encoded CPD photolyase and that the gene duplication of the ancestral proteins had occurred at least eight times before the divergence between eubacteria and eukaryotes.
光解酶-蓝光光感受器家族由环丁烷嘧啶二聚体（CPD）光解酶、（6-4）光解酶和蓝光光感受器组成。CPD光解酶和（6-4）光解酶分别参与CPD和（6-4）光产物的光复活作用。基于氨基酸序列相似性，CPD光解酶可分为I类和II类两个亚类。蓝光光感受器是植物早期发育必不可少的光探测器。该感受器的氨基酸序列与光解酶的相似，尽管该感受器不具有光复活活性。为了研究该家族的功能差异，对这些蛋白质的氨基酸序列进行了比对。比对结果表明，I类CPD光解酶（I类光解酶）的辅因子和底物识别机制与II类CPD光解酶（II类光解酶）不同。我们根据比对结果，用邻接法（NJ）和最大似然法（ML）重建了系统发育树。系统发育分析表明，该家族的祖先基因编码CPD光解酶，且在真细菌和真核生物分化之前，祖先蛋白质的基因复制至少发生了八次。
