Australian Research Council Centre of Excellence in Plant Energy Biology, University of Western Australia, 35 Stirling Highway, Crawley 6009, WA, Australia.
New Phytol. 2011 Jul;191(1):37-47. doi: 10.1111/j.1469-8137.2011.03746.x. Epub 2011 May 9.
The pentatricopeptide repeat (PPR) is a degenerate 35-amino-acid structural motif identified from analysis of the sequenced genome of the model plant Arabidopsis thaliana. From the wealth of sequence information now available from plant genomes, the PPR protein family is now known to be one of the largest families in angiosperm species, as most genomes encode 400-600 members. As the number of PPR genes is generally only c. 10-20 in other eukaryotic organisms, including green algae, the family has obviously greatly expanded during land plant evolution. This provides a rare opportunity to study selection pressures driving a 50-fold expansion of a single gene family. PPR proteins are sequence-specific RNA-binding proteins involved in many aspects of RNA processing in organelles. In this review, we will summarize our current knowledge about the evolution of PPR genes, and will discuss the relevance of the dramatic expansion in the family to the functional diversification of plant organelles, focusing primarily on RNA editing.
五肽重复（PPR）是从模式植物拟南芥的测序基因组分析中鉴定出的一种退化的 35 个氨基酸结构基序。从现在植物基因组中大量可用的序列信息来看，PPR 蛋白家族现在被认为是被子植物物种中最大的家族之一，因为大多数基因组编码 400-600 个成员。由于其他真核生物，包括绿藻，其 PPR 基因的数量通常只有约 10-20 个，因此该家族在陆地植物进化过程中显然大大扩张了。这为研究驱动单个基因家族 50 倍扩张的选择压力提供了一个难得的机会。PPR 蛋白是序列特异性的 RNA 结合蛋白，参与细胞器中 RNA 加工的许多方面。在这篇综述中，我们将总结我们目前对 PPR 基因进化的认识，并将讨论该家族的急剧扩张与植物细胞器功能多样化的相关性，主要集中在 RNA 编辑上。
