Function: Recruits TFIIH to the initiation complex and stimulates the RNA polymerase II C-terminal domain kinase and DNA-dependent ATPase activities of TFIIH. Both TFIIH and TFIIE are required for promoter clearance by RNA polymerase. similarity: Belongs to the TFIIE beta subunit family. similarity: Contains 1 TFIIE beta DNA-binding domain. subunit: Tetramer of two alpha and two beta chains. Interacts with FACT subunit SUPT16H.