2.13 Electrophoretic mobility shift assay (EMSA)
The electrophoretic mobility shift assay was conducted using an RNA EMSA Kit (BersinBio, Guangzhou, China) according to the manufacturer’s instructions. Briefly, the full‐length CDS of MeCSP5  was amplified by PCR and then cloned into the pCzn1‐His to express the MeCSP5 protein in Escherichia coli  DE3 strain. The recombinant MeCSP5 protein was purified using the Ni affinity chromatography. EMSA was performed in a reaction mixture containing MeCSP5 proteins and biotin-labeled CRIR1 RNA probes. Negative control assays were performed by adding 100-fold excesses of unlabeled RNA probes to the reaction mixture. After electrophoresis and incubation, signals were recorded and analyzed.