Input of energy in the form of ATP is required at several stages for the prepriming reaction, and it is required for unwinding DNA.

The helicase action of DnaB depends on ATP hydrolysis, and the swivel action of gyrase requires ATP hydrolysis.

ATP also is needed for the action of primase and to load the b subunit of Pol III in order to initiate DNA synthesis.

TLS Online TPP Program

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#Unit 3. Fundamental Processes

Core enzyme binds indiscriminately to any DNA. Sigma factor reduces the affinity for sequence-independent binding and confers specificity for promoters.

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#Unit 3. Fundamental Processes

Holoenzyme binds to promoters much more tightly, with an association constant ,1000 times higher on average and a half-life that can be as long as several hours

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#Unit 3. Fundamental Processes

significantly higher dissociation rate at 25C than at 37C, and a much higher dissociation rate at 15C. Because high temperature promotes DNA melting

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#Unit 3. Fundamental Processes

TLS Online TPP Program

#Id: 6284

#Unit 3. Fundamental Processes

Mechanism: How Polymerase Find Promoter Sequences

TLS Online TPP Program

#Id: 6285

#Unit 3. Fundamental Processes