The two cores have different abilities to dissociate from DNA. This corresponds to the need to synthesize 

a continuous leading strand (where polymerase remains associated  with the template) and 

a discontinuous lagging strand (where polymerase repetitively dissociates and reassociates)

TLS Online TPP Program

#Id: 6491

#Unit 3. Fundamental Processes

Four TAFs do have some intrinsic DNA binding ability: TAF4b, TAF12, TAF9, and TAF6 are (distant) homologs of histones H2A, H2B, H3, and H4, respectively.  TAF4b/TAF12 and TAF9/TAF6 form heterodimers using the histone fold motif

TLS Online TPP Program

#Id: 6492

#Unit 3. Fundamental Processes

Binding of the TFIID complex in the initiation reaction regularly protects the region from -45 to -10.

TLS Online TPP Program

#Id: 6493

#Unit 3. Fundamental Processes

TLS Online TPP Program

#Id: 6494

#Unit 3. Fundamental Processes

Model of Formation of the DABPolF Complex

TLS Online TPP Program

#Id: 6495

#Unit 3. Fundamental Processes

TFIIB, TFIIE, and TFIIH are required to melt DNA to allow polymerase movement. The last factors to join the initiation complex are TFIIE and TFIIH. 

TLS Online TPP Program

#Id: 6496

#Unit 3. Fundamental Processes

TFIIH is the only general transcription factor that has multiple independent enzymatic activities. Its several activities include an ATPase, helicases of both polarities, and a kinase activity that can phosphorylate the CTD tail of RNA polymerase II (on serine 5 of the heptapeptide repeat). TFIIH is an exceptional factor that may also play a role in elongation.