Taq polymerase

Taq polymerase is an enzyme found in Thermus aquaticus, an organism which live in environments of extremely high temperatures, such as hot springs. It is therefore extremely thermostable, hence known as thermophilic bacterium. The enzyme is commonly used in Polymerase Chain Reaction (PCR) as it can withstand the required high temperatures (95 degrees celsius) of the Thermo Cycler, while retaining its enzymatic functions.

During PCR, Taq polymerase is used to extend the primers. This is due to the fact that during PCR the reaction is heated to 95°C and normal DNA Polymerase III would be denatured by the high temperature in the reaction. Alternatively, Pfu is another thermostable DNA polymerase that may be used in PCR, this has a proof reading ability and is therfore more accurate . DNA Taq polymerase can also stand at a temperature of 37 degrees for 7 days without losing its activity. It has a terminal transferase activity involving adding of a nucleotide one at a time to the 3' end.

References

     3. http://taqpolymerase.net/