as co-factor helps enzyme to work better!
Look! Mg is a kind of pickle for enzyme! He can eat more!!!! or work more!
I thnk this article might help a bit!!..... pretty late response, I know... But still, if it helps someone out!!
Dear i agree with you...Mostafa Akbarzadeh Khiavi
Magnesium ion concentration can affect the specifity and efficiency of the reaction and is therefore identified as a critical component. Almost all polymerases require divalent cations for their activity but some tend to function in buffers containing Mn2+ as well, although a little less efficiently. dNTPs and oligonucleotides bind to Mg2+ and therefore its concentration should exceed the molar concentration of phosphate groups that are contributed from both the dNTPs and primers. dNTPs bind in equimolar concentration with Mg2+. Chelating agents (EDTA) and negatively charged ions from the DNA template buffer can also sequester Mg2+ and this to be minimized. The polymerase enzyme functions actively in higher concentrations of Mg2+ and has lower fidelity i.e. the enzyme is more error prone at excess concentration of the Mg2+ ions. Magnesium ion concentration can be lowered, so that the polymerases are barely processive. This will result in higher fidelity of amplification. The concentration of Mg2+ is dependent on the empirical proportions of template and primer DNA and will need to be standardized for an experiment. Polymerase activity when plotted against the Mg2+ gives a bell curve, and the highest activity is seen at 1.2 to 1.3mM. Standard PCR buffers contain 1.5mM of MgCl2
Taq polymerase can't function efficiently without MgCl2, so we must use MgCl2 in PCR reaction for polymerase to function.
Amanda C Mitchell
Icahn School of Medicine at Mount Sinai
Karima Akool Al-Salihi
University of Nottingham
Universidad Peruana Cayetano Heredia
University of Geneva
Central Michigan University
Rachel O' Dea
National University of Ireland, Galway
Susana Duarte Ferreira
University of Aveiro
National Yang Ming University
Gebze Technical University