Systematic analysis on RNA recognition mechanism of PPR protein for plant organelle gene expression

五肽重复序列(PPR)蛋白是真核生物中普遍存在的RNA结合蛋白。细胞器转录的处理和稳定性是由PPR蛋白以基因特异性的方式介导的，通过串联的简并的35个氨基酸重复单位阵列识别，PPR基序。在这里，我们展示了参与RNA编辑的PPR蛋白识别RNA的原理。基序中3个特定位置的氨基酸变异决定了以可编程的方式识别特定RNA，1-基序与1-核苷酸对应。这3种氨基酸的编码核苷酸频率数据被用来为几个PPR蛋白分配准确的相互作用位点，以便进行RNA编辑，并预测一个未鉴定的PPR蛋白的靶点。在另一种观点中，PPR蛋白似乎提供了一个非常有希望的机会来创建具有定制特异性的定制RNA结合蛋白。

Pentatricopeptide repeat (PPR) proteins are eukaryotic RNA-binding proteins that are commonly found in plants. Organelle transcript processing and stability are mediated by PPR proteins in a gene-specific manner through recognition by tandem arrays of degenerate 35-amino-acid repeating units, the PPR motifs. Here, we showed the principle underlying RNA recognition for PPR proteins involved in RNA editing. Amino acid variation at 3 particular positions within the motif determined recognition of a specific RNA in a programmable manner, with a 1-motif to 1-nucleotide correspondence,. Data from the decoded nucleotide frequencies for these 3 amino acids were used to assign accurate interacting sites to several PPR proteins for RNA editing and to predict the target sites for an uncharacterized PPR proteins. In another view, PPR proteins appear to provide an extremely promising opportunity to create custom RNA binding proteins with tailored specificity.