Rb protein regulation by G1 CDKs in mammalian cells is analogous to Whi5 regulation by Cln3-CDK in yeast.

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#Unit 3. Fundamental Processes

Replicons in euchromatin initiate before replicons in heterochromatin

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#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.

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#Unit 3. Fundamental Processes

From the speed of replication, it is evident that a mammalian genome could be replicated in 1 hour if all replicons functioned simultaneously. S phase actually lasts for 6 hours in a typical somatic cell, though, which implies that no more than 15% of the replicons are likely to be active at any given moment.

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#Unit 3. Fundamental Processes

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#Unit 3. Fundamental Processes

#Id: 5998

#Unit 3. Fundamental Processes

An ARS element consists of an A-T–rich region that contains discrete sites in which mutations affect origin function.