GO:0001129:   RNA polymerase II transcription factor activity, TBP-class protein binding, involved in preinitiation complex assembly
Interacting selectively and non-covalently with a member of the class of TATA-binding proteins (TBP), including any of the TBP-related factors (TRFs), to facilitate the aggregation, arrangement and bonding together of proteins on RNA polymerase II promoter DNA to form the transcriptional preinitiation complex (PIC), the formation of which is a prerequisite for transcription by RNA polymerase.