Tag:ADARcd(E488Q) corresponds to the catalytic domain of the RNA-editing enzyme encoded by the Drosophila melanogaster Adar gene, mutated to carry the 'hyperactive' E488Q amino acid substitution. When fused to an RNA-binding protein of interest, Tag:ADARcd(E488Q) is targeted in vivo to the RNA targets of the tagged RNA-binding protein, resulting in these RNAs being marked permanently by an editing event. The editing events can subsequently be identified by sequencing, permitting identification of the in vivo targets of the RNA-binding protein. Tag:ADARcd(E488Q) shows increased editing activity compared to Tag:ADARcd (FBrf0239332).