TFIIIB assembly

Dumay-Odelot, H., Acker, J., Arrebola, R., Sentenac, A., and Marek, C. (2002). Multiple roles of the taul31 subunit of yeast transcription factor IIC (TFIIIC) in TFIIIB assembly. Mol. Cell. Biol. 22, 298-308. 

Marek, C., Lefebvre, O., Carles, C., Riva, M., Chaussivert, N., Ruet, A., and Sentenac, A. (1993). The TFIIIB assembling subunit of yeast transcription factor TFIIIC has both tetratricopoptide repeats and basic helix loop-helix motifs. Proc. Natl. Acad. Sci. USA 90, 4027-4031. 

After TFIIIA binds, proteins TFIIIC and then TFII-IB also bind. Although promoters of classes 2 and 3 do not require TFIIIA, all three classes depend upon TFIIIB and TFIIIC.484 The TATA-binding protein TBF is one of three components present in TFIIIB, which may be regarded as the true initiation factor.47 485 Both TFIIIA and TFIIIC can be described as assembly factors 47 A silkworm RNA pol III has been reported to require a transcription factor consisting of RNA 486... 

Three general transcription factors are required for Pol III to Initiate transcription of tRNA and SS-rRNA genes In vitro. Two multimeric factors, TFIIIC and TFIIIB, participate In Initiation at both tRNA and SS-rRNA promoters a third factor, TFIIIA, Is required for initiation at SS-rRNA promoters. As with assembly of Pol I and Pol II Initiation complexes, the Pol III general transcription factors bind to promoter DNA in a defined sequence. 

TETRATRICOPEPTIDE REPEATS OF TFC4 AND A LIMITING STEP IN THE ASSEMBLY OF THE INITIATION FACTOR TFIIIB... 

This chapter focuses on recent advances in our understanding of a critical limiting step in Pol III transcription the assembly on DNA of the initiation factor TFIIIB by TFIIIC. 

In contrast to its minor role in TATA-directed assembly of TFIIIB, the TBlIB-like region of Brfl plays a major role in Pol III recruitment and promoter melting (Hahn and Roberts, 2000 Kassavetis et al., 1998, 2001). The TFIIB-core region of Brfl is sufficient for a binary interaction with two Pol Ill-specific subunits, Rpcl7 and Rpc34 (Ferri et al., 2000 Khoo et al.,... 

Last, understanding the complex mechanism by which Tfc4 interacts with TFIIIB subunits may provide a paradigm for understanding how multiple TPR arrays contribute to the assembly and function of multisubunit complexes. 

Kassavetis, G. A., Bardeleben, C., Kumar, A., Ramirez, E., and Geiduschek, E. P. (1997). Domains of the Brf component of RNA polymerase III transcription factor IIIB (TFIIIB) functions in assembly of TFIIIB-DNA complexes and recruitment of RNA polymerase to the promoter. Mol. Cell. Biol. 17, 5299-5306. 

Kassavetis, G. A., Joazeiro, C. A., Pisano, M., Geiduschek, E. P., Colbert, T., Hahn, S., and Blanco, J. A. (1992). The role of the TATA-binding protein in the assembly and function of the multisubunit yeast RNA polymerase III transcription factor, TFIIIB. Cell 71, 1055-1064. 

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