Inactive X chromosome also becomes associated with PRC2 complexes, which catalyze the trimethylation of histone H3 lysine 27. This methylation results in association of the PRC1 complex and transcriptional repression

TLS Online TPP Program

#Id: 5051

#Unit 3. Fundamental Processes

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

TLS Online TPP Program

#Id: 5052

#Unit 3. Fundamental Processes

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.

TLS Online TPP Program

#Id: 5053

#Unit 3. Fundamental Processes

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

TLS Online TPP Program

#Id: 5054

#Unit 3. Fundamental Processes

Phospholipids promote the exchange of ATP with ADP bound to DnaA

TLS Online TPP Program

#Id: 5055

#Unit 3. Fundamental Processes

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

TLS Online TPP Program

#Id: 5056

#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.