Molecular insights into RNA recognition by the ZAR1 C-terminal domain.

Zygote arrested-1 (ZAR1)-dependent translational repression plays an important role during early oogenesis. Here, we solved the crystal structure of the C-terminal domain of ZAR1, which contains three zinc-binding motifs, and confirmed its ability to bind to RNAs derived from translation control sequence elements within the 3'-UTRs of Wee1 and Mos mRNAs. By using the AlphaFold server, we obtained a predicted model for the structure of the ZAR1 C-terminal domain bound with a 13-nt RNA. Mutagenesis and biochemistry experiments further validated the ZAR1-RNA interaction. Therefore, our study provides insights into RNA recognition by the ZAR1 zinc-binding domain and the role of ZAR1 in repressing gene expression. Impact statement Zygote arrested-1 (ZAR1)-dependent translational repression finely orchestrates gene expression during early oogenesis. Here, we solved the high-resolution structure of the C-terminal zinc-binding domain of ZAR1 and confirmed its binding to RNA. The modeled ZAR1-RNA complex by Alphafold further provides insight into RNA recognition by ZAR1.