PPR蛋白家族是一类具有序列特异性的RNA结合蛋白，参与真核RNA的转录、剪接、编辑和稳定等多种代谢途径，与植物细胞质雄性不育有直接关系。在人类中，PPR蛋白还与神经衰退性疾病相关。.PPR蛋白由2-30个数目不等的重复基序串联而成，每个基序一般含有35个氨基酸，可以特异性地识别一个RNA碱基，第5位和第35位的氨基酸在识别过程中发挥关键作用，合称识别密码。近期本课题组报道了一套高效、快速组装人工设计的PPR蛋白的方法，并破解了PPR基序中的识别密码与RNA碱基之间的对应关系。但是这些识别密码与RNA碱基之间的识别机制仍需进一步研究。本项目通过结构生物学和生物化学的方法，解析含不同识别密码的PPR蛋白与对应RNA的复合物的结构，揭示二者互作的分子机制。为优化PPR基序的序列提供参考，为促进以PPR为基础的RNA水平上的细胞器基因操作工具的开发奠定基础。

Pentatricopeptide repeat (PPR) proteins are a family of specific RNA binding proteins. PPR proteins (PPRs) mediate multiple aspects of RNA metabolism such as RNA transcription, processing, editing, and stability. PPRs function as fertility restore gene in plants. PPRs also associated with human neurodegenerative disease. .PPRs contain 2-30 tandem repeats. Each repeat typically comprises 35 amino acids. PPRs bind to their target single-stranded RNA (ssRNA) in a modular and base-specific fashion and that the 5th and 35th amino acids play key roles in recognition termed as recognition code. Recently, we developed a modular assembly method for high-throughput construction of designer PPRs and systematically delineated the correlation between PPR codes and RNA bases. However, the structural basis for nucleotide-specific recognition by code-containing designer PPR (dPPR) remains to be elucidate. Here, we aim to obtain the structures of various PPR-RNA complex. This will lay a solid foundation on optimizing the PPR motif as well as accelerating the development of PPR-dependent RNA tools in organelle gene manipulation.