Open AccessSequence of general transcription factor TFIIB and relationships to other initiation factors.
Author(s) -
Sohail Malik,
Koji Hisatake,
Hideki Sumimoto,
Masami Horikoshi,
Robert G. Roeder
Publication year - 1991
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.88.21.9553
Subject(s) - transcription factor ii a , transcription factor ii b , transcription factor ii f , transcription preinitiation complex , transcription factor ii d , rna polymerase ii holoenzyme , biology , general transcription factor , transcription factor ii e , tata box , genetics , microbiology and biotechnology , polymerase , promoter , rna dependent rna polymerase , gene , gene expression
Transcription factor TFIIB is a ubiquitous factor required for transcription initiation by RNA polymerase II. Previous studies have suggested that TFIIB serves as a bridge between the "TATA"-binding factor (TFIID) and RNA polymerase II during preinitiation complex assembly and, more recently, that TFIIB can be a target of acidic activators. We have purified TFIIB to homogeneity, shown that activity resides in a 33-kDa polypeptide, and obtained cDNAs encoding functional TFIIB. TFIIB contains a region with amino acid sequence similarity to a highly conserved region of prokaryotic sigma factors. This is consistent with analogous functions for these factors in promoter recognition by RNA polymerases and with similar findings for TFIID, TFIIE, and TFIIF/RAP30. Like TFIID, TFIIB contains both a large imperfect repeat that could contribute an element of symmetry to the folded protein and clusters of basic residues that could interact with acidic activator domains. These findings argue for a common origin of TFIIB, TFIID, and other general transcription factors and for the evolutionary segregation of complementary functions.