Pfu polymerase in PCR

Dr. Duncan Clark duncan at
Wed Feb 19 11:39:47 EST 1997

In article <Pine.HPP.3.91.970218134513.23388B-
100000 at fhs.csu.McMaster.CA>, Martin Hughes <mhughes at fhs.csu.McMaster.CA>
>As I 
>understand it, the proofreading enzymes have their exonuclease activity 
>as a subunit of the enzyme, which 'proofreads' as the strand is 
>synthesised, comparing the daughter strand to the parent. 

It isn't a real separate subunit in that it is two domains on the same
protein of approx 94kDa.

The processivity of Taq is reported at around 60 bases. Stoffel is less
at I think 18-25 bases.

I tend to look at it as the Taq synthesises until it either jumps off
having done say 60bp or it jumps off 'cos it has put in the wrong base
and the Pfu or whatever then comes along corrects the misincorporated
base, synthesises some more (I don't know how many) then jumps off etc.
the whole process repeats until the end of the template is reached.

The problem with being on the cutting edge is that you occasionally get 
sliced from time to time....

Duncan Clark
DNAmp Ltd.
TEl/FAX 01252376288

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