The class 1 release factor is required in termination of protein synthesis. It could accurately recognize the stop signal and promotes the hydrolysis of the ester bond linking the polypeptide chain with the peptidyl (p)site tRNA. The model of “molecular mimicry between release factor and tRNA” explains the resemblance of function. Its highly conserved, universal GGQ motif and a tripeptide ‘anticodon’ play important roles in translation termination respectively.