Encyclopedia of Systems Biology

2013 Edition
| Editors: Werner Dubitzky, Olaf Wolkenhauer, Kwang-Hyun Cho, Hiroki Yokota

PIC Assembly Pathways

Reference work entry
DOI: https://doi.org/10.1007/978-1-4419-9863-7_1564



There are two possible PIC ( pre- initiation complex) assembly pathways in the RNAPII system (Lee and Young 2000; Thomas and Chiang 2006) (Fig.  1). In the sequential assembly pathway (Model 1), TFIID binds to the core promoter, and then the binary TFIID-DNA complex incorporates TFIIA, TFIIB, RNAPII/TFIIF, TFIIE, and TFIIH in a stepwise manner. In the holoenzyme recruitment pathway (Model 2), a huge RNAPII complex, the so-called holoenzyme containing not only GTFs (TFIIB, E, F, and H) but also Mediator and/or some ATP-dependent chromatin remodelers is incorporated at once into the TFIID-TFIIA-DNA complex that is pre-formed in the same manner as in the sequential assembly pathway. Although both pathways are plausible and supported by the evidence obtained in vitro, it is difficult to determine which pathway operates on the promoters of individual genes in living cells. Note that two similar pathways are also...
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  1. Lee TI, Young RA (2000) Transcription of eukaryotic protein-coding genes. Annu Rev Genet 34:77–137PubMedGoogle Scholar
  2. Thomas MC, Chiang CM (2006) The general transcription machinery and general cofactors. Crit Rev Biochem Mol Biol 41(3):105–178PubMedGoogle Scholar

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© Springer Science+Business Media, LLC 2013

Authors and Affiliations

  1. 1.Department of Supramolecular BiologyGraduate School of Nanobioscience, Yokohama City UniversityYokohamaJapan