 gw182-family proteins are essential for microrna - mediated translational repression and deadenylation in animal cells . here we show that a conserved motif in the human gw182 paralog tnrc6c interacts with the c - terminal domain of polyadenylate binding protein 1 ( pabc ) and present the crystal structure of the complex 
 . mutations at the complex interface impair mrna deadenylation in mammalian cell extracts , suggesting that the gw182-pabc interaction contributes to microrna - mediated gene silencing . 
Supplementary Material