Rab GTPases 

associate with transport vesicles and act as key regulators of vesicle trafficking to and fusion with the appropriate target membrane.

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DnaA ATPase activity is stimulated by membrane phospholipids and single-stranded DNA.

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DnaA-ATP in an extended multimeric state promoted by the accessory protein DiaA, which stimulates cooperative binding of DnaA.

DnaA-ATP binds cooperatively to form a helical central core around which oriC DNA is wrapped.

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DnaA has a weak ATPase intrinsic activity which is enhanced by a factor termed Hda.

In a conceptually elegant feedback loop, Hda is recruited to a replication origin via the b subunit of the DNA polymerase. it acts to switch off DnaA

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Phospholipids promote the exchange of ATP with ADP bound to DnaA

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DnaA then acts at three A-T–rich 13-bp tandem repeats located on the left side of oriC.

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#Unit 3. Fundamental Processes

Initiation of replication at oriC starts with formation of a complex that ultimately requires six proteins: DnaA, DnaB, DnaC, HU, gyrase, and SSB.