A second function of small GTPases in vesicle formation is in the pinching off of a completed vesicle from the parent membrane

TLS Online TPP Program

#Id: 2937

#Unit 3. Fundamental Processes

DnaA is provided by its response to phospholipids. Phospholipids promote the exchange of ATP with ADP bound to DnaA.

TLS Online TPP Program

#Id: 2938

#Unit 3. Fundamental Processes

While DnaA has a weak intrinsic activity that converts the ATP to ADP, this is enhanced by a factor termed Hda.

TLS Online TPP Program

#Id: 2939

#Unit 3. Fundamental Processes

Hda recruited, it acts to switch offDnaA, preventing a second round of replication.

TLS Online TPP Program

#Id: 2940

#Unit 3. Fundamental Processes

Note that a crudal difference between replication in bacteria and replication in eukaryotes is that in bacteria replication is occurring on DNA, while in eukaryotes replication is occurring on chromatin and nucleosomes play a role so their presence must be taken into account.

TLS Online TPP Program

#Id: 2941

#Unit 3. Fundamental Processes

A eukaryotic chromosome contains multiple origins of replication that ultimately merge during replication.

TLS Online TPP Program

#Id: 2942

#Unit 3. Fundamental Processes

The rate of replication is -2000 bp/min, which is much slower than the 50,000 bp/min of bacterial replication fork movement, presumably because the chromosome is assembled into chromatin, not naked DNA.