Poly-Histidine Tag (His-tag) is also used as tag to separate protein

TLS Online TPP Program

#Id: 743

#Unit 3. Fundamental Processes

TLS Online TPP Program

#Id: 744

#Unit 3. Fundamental Processes

free energy for this reaction is rather small (DG–3.5 kcal/mol).

TLS Online TPP Program

#Id: 745

#Unit 3. Fundamental Processes

Additional free energy for the formation of phosphodiester bond is provided by the rapid hydrolysis of the pyrophosphate into two phosphate groups by an enzyme known as pyrophosphatase:

 

TLS Online TPP Program

#Id: 746

#Unit 3. Fundamental Processes

Hydrolysis of pyrophosphate makes phosphodiester bond a highly favorable reaction with a DG of –7 kcal/mol, which corresponds to an equilibrium constant (Keq) of 105.

TLS Online TPP Program

#Id: 747

#Unit 3. Fundamental Processes

A:T and G:C base pairs have same geometry that’s why DNA polymerase has only one catalytic site for polymerization 

TLS Online TPP Program

#Id: 748

#Unit 3. Fundamental Processes

Incorrect base pairing leads to dramatically lower rates of nucleotide addition called as kinetic proofreading