Gully Benjamin S, Cowieson Nathan, Stanley Will A, Shearston Kate, Small Ian D, Barkan Alice, Bond Charles S
School of Chemistry and Biochemistry, The University of Western Australia, Crawley, Western Australia, Australia.
SAXSWAXS beamline, Australian Synchrotron, 800 Blackburn Road, Clayton, Victoria, Australia.
Nucleic Acids Res. 2015 Feb 18;43(3):1918-26. doi: 10.1093/nar/gkv027. Epub 2015 Jan 21.
The pentatricopeptide repeat (PPR) protein family is a large family of RNA-binding proteins that is characterized by tandem arrays of a degenerate 35-amino-acid motif which form an α-solenoid structure. PPR proteins influence the editing, splicing, translation and stability of specific RNAs in mitochondria and chloroplasts ZEA MAYS: PPR10 is amongst the best studied PPR proteins, where sequence-specific binding to two RNA transcripts, ATPH: and PSAJ, HAS BEEN DEMONSTRATED TO FOLLOW: a recognition code where the identity of two amino acids per repeat determines the base-specificity. A recently solved ZmPPR10: PSAJ: complex crystal structure suggested a homodimeric complex with considerably fewer sequence-specific protein-RNA contacts than inferred PREVIOUSLY: Here we describe the solution structure of the ZmPPR10: ATPH: complex using size-exclusion chromatography-coupled synchrotron small-angle X-ray scattering (SEC-SY-SAXS). Our results support prior evidence that PPR10 binds RNA as a monomer, and that it does so in a manner that is commensurate with a canonical and predictable RNA-binding mode across much of the RNA-protein interface.
五肽重复（PPR）蛋白家族是一类庞大的RNA结合蛋白家族，其特征是由一个35个氨基酸的简并基序串联排列形成α-螺旋管结构。PPR蛋白影响线粒体和叶绿体中特定RNA的编辑、剪接、翻译和稳定性。玉米：PPR10是研究得较为深入的PPR蛋白之一，已证明其与两个RNA转录本ATPH和PSAJ的序列特异性结合遵循一种识别密码，即每个重复序列中两个氨基酸的身份决定碱基特异性。最近解析的ZmPPR10:PSAJ复合物晶体结构表明，该复合物为同二聚体，其序列特异性蛋白质-RNA接触比之前推断的要少得多。在此，我们使用尺寸排阻色谱-同步加速器小角X射线散射（SEC-SY-SAXS）描述了ZmPPR10:ATPH复合物的溶液结构。我们的结果支持了先前的证据，即PPR10以单体形式结合RNA，并且在很大程度上通过一种规范且可预测的RNA结合模式在RNA-蛋白质界面上进行结合。
