Restoration ecology is the full or partial repair or replacement of biological habitats and/or their populations that have been degraded or destroyed.

TLS Online TPP Program

#Id: 6019

#Unit 3. Fundamental Processes

TLS Online TPP Program

#Id: 6020

#Unit 3. Fundamental Processes

As cells enter into the S phase of the cell cycle, two kinases, CDK and DDK, are activated.  DDK phosphorylates loaded Mcm2-7 helicase, and CDK phosphorylates Sld2 and Sld3.Phosphorylated Sld2 and Sld3 bind to Dpb11, and together these proteins facilitate binding of the helicase-activating proteins, Cdc45 and GINS, to the helicase.  

TLS Online TPP Program

#Id: 6021

#Unit 3. Fundamental Processes

Cdc45 and GINS form a stable complex with the Mcm2-7 helicase (called the Cdc45/ Mcm2-7/GINS, or CMG, complex) and dramatically activate Mcm2-7 helicase activity.

TLS Online TPP Program

#Id: 6022

#Unit 3. Fundamental Processes

The leading-strand DNA polymerase (E) is recruited to the helicase at this stage (before DNA unwinding). After formation of the CMG complex, Sld2, Sld3, and Dpb11 are released from the origin. 

TLS Online TPP Program

#Id: 6023

#Unit 3. Fundamental Processes

DNA Pol a/ primase and DNA Pol d (which primarily act on the lagging strand) are only recruited after DNA unwinding.

TLS Online TPP Program

#Id: 6024

#Unit 3. Fundamental Processes

DNA polymerase a is unusual because it has the ability to initiate a new strand. It is used to initiate both the leading and lagging strands. 

The enzyme exists as a complex consisting of a 180-kD catalytic (DNA polymerase) subunit, which is associated with three other subunits: the B subunit that appears necessary for assembly, and two small subunits that provide the primase (RNA polymerase) activity.  It has dual capacity to prime and extend chains, this complex is often called pol a/primase.