Re. Meyers et Pa. Sharp, TATA-BINDING PROTEIN AND ASSOCIATED FACTORS IN POLYMERASE-II AND POLYMERASE-III TRANSCRIPTION, Molecular and cellular biology, 13(12), 1993, pp. 7953-7960
Transcription by RNA polymerase I (pol I), pol II, and pol III require
s the TATA-binding protein (TBP). This protein functions in associatio
n with distinct TBP-associated factors (TAFs) which may specify the na
ture of the polymerase selected for initiation at a promoter site. In
the pol III transcription system, the TBP-TAF complex is a component o
f the TFIIIB factor. This factor has been resolved into a TBP-TAF comp
lex and another component, both of which are required for reconstituti
on of transcription by pol III. Neither the TBP-TAF complexes B-TFIID
and D-TFIID, which were previously characterized as active for pol II
transcription, nor TBP alone can complement pol III transcription reac
tions that are dependent upon the TBP-TAF subcomponent of TFIIIB. Surp
risingly, the TBP-TAF subcomponent of TFIIIB is active in reconstituti
on of pol II transcription.