Taq polymerase: Difference between revisions

Revision as of 03:22, 23 June 2006

Revision as of 03:23, 23 June 2006

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[[Image:TaqPol.jpg|thumb|Structure of Taq polymerase]]

'''Taq polymerase''' ("Taq Pol," or simply "Taq", from "Thermus aquaticus") is a thermostable [[polymerase]] used [[PCR|polymerase chain reaction]] to check for the presence or absence of a putative gene by attempting to amplifycreating a geneDNA fragment. First isolated from ''[[Thermus aquaticus]]'', a [[bacterium]] that lives in [[hot springs]] and [[hydrothermal vent]]s, Taq was identified as the first polymerase able to withstand the denaturing conditions required during PCR. Its enzymatic activity [[halflife]] at 95 degrees [[Celsius]] is 1.6 hours.

One of Taq polymerases major drawbacks is its low replication [[fidelity]]. Without a 3' to 5' [[exonuclease]] [[proofreading]] capacity to replace an accidental mismatch in the newly [[Chemical synthesis|synthesized]] [[DNA]] strand, Taq polymerase cannot be used in experiments where an identical genetic sequence is required, such as in molecular cloning. Commerically sold Taq DNA polymerase has an error rate of one in 10,000 nucleotides and typically produces 16% of mutated 1kb (kilobasepair) PCR products in a reaction. It can amplify a 1kb strand of DNA in roughly 30 seconds at 72°C.