Molecular Evolution and Functional Diversification of Replication Protein A1 in Plants.
Molecular Evolution and Functional Diversification of Replication Protein A1 in Plants.
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DOI：
10.3389/fpls.2016.00033
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发表时间：
2016
影响因子：
5.6
通讯作者：
Culligan KM
中科院分区：
文献类型：
--
作者：
Aklilu BB;Culligan KM
复制蛋白A（RPA）是真核生物DNA复制、修复和重组所需的异源三聚体单链DNA结合复合物。RPA由RPA 1、RPA 2和RPA 3三个亚基组成。与通常在动物和酵母中发现的单个RPA亚基基因相反，植物编码RPA亚基的多个旁系同源物，表明亚功能化。遗传分析表明，5个拟南芥RPA 1旁系同源物（RPA 1A至RPA 1 E）在DNA复制、修复和减数分裂中具有独特和重叠的功能。我们假设RPA 1亚功能将反映在旁系同源物之间的主要结构和序列差异中。为了解决这一问题，我们分析了RPA 1旁系同源物的氨基酸和核苷酸序列，从25个完整的基因组，代表了广泛的植物和单细胞绿色藻类。我们发现植物RPA 1基因家族分为RPA 1A、RPA 1B和RPA 1C三大类，它们可能起源于单细胞绿色藻类的两个祖先类群。在菊科中，RPA 1B和RPA 1C组进一步扩展，分别包括两个独特的亚功能旁系同源物RPA 1D和RPA 1 E。此外，RPA 1组具有独特的结构域，基序，顺式元件，基因表达谱和模式的保护，是一致的建议功能在单子叶植物和双子叶植物物种，包括一个新的C-末端锌指结构域，发现只有在植物RPA 1C样序列。这些结果允许在新测序的植物基因组中改进RPA 1亚基功能的预测，并可能提供一个独特的分子工具，以改善菊科物种的分类。
Replication protein A (RPA) is a heterotrimeric, single-stranded DNA binding complex required for eukaryotic DNA replication, repair, and recombination. RPA is composed of three subunits, RPA1, RPA2, and RPA3. In contrast to single RPA subunit genes generally found in animals and yeast, plants encode multiple paralogs of RPA subunits, suggesting subfunctionalization. Genetic analysis demonstrates that five Arabidopsis thaliana RPA1 paralogs (RPA1A to RPA1E) have unique and overlapping functions in DNA replication, repair, and meiosis. We hypothesize here that RPA1 subfunctionalities will be reflected in major structural and sequence differences among the paralogs. To address this, we analyzed amino acid and nucleotide sequences of RPA1 paralogs from 25 complete genomes representing a wide spectrum of plants and unicellular green algae. We find here that the plant RPA1 gene family is divided into three general groups termed RPA1A, RPA1B, and RPA1C, which likely arose from two progenitor groups in unicellular green algae. In the family Brassicaceae the RPA1B and RPA1C groups have further expanded to include two unique sub-functional paralogs RPA1D and RPA1E, respectively. In addition, RPA1 groups have unique domains, motifs, cis-elements, gene expression profiles, and pattern of conservation that are consistent with proposed functions in monocot and dicot species, including a novel C-terminal zinc-finger domain found only in plant RPA1C-like sequences. These results allow for improved prediction of RPA1 subunit functions in newly sequenced plant genomes, and potentially provide a unique molecular tool to improve classification of Brassicaceae species.