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Unformatted text preview: m? Mg2+ ion A activates the “primer” 3/-OH for nucleophilic attack on the alpha phosphorus (and
also helps to orient it and electrostatically stabilize it) while Mg2+ ion B orients the triphosphate
group and electrostatically stabilizes it
Describe the ways in which the fidelity of the reaction is ensured.
~ equal concentrations of deoxynucleotide triphosphate substrates in pool
2-stage DNA pol reaction which tightens the active site to facilitate the reaction when
there is good base pairing with the incoming dNTP and the template
3/ -> 5/exonuclease activity with DNA pol δ and ε
DNA repair mechanisms especially MMR & BER 11 Initials:___________________
32. 10 pts
XPA, RPA, XPC-TRIIH, XPB (a 3’->5’ helicase) & XPD (a 5’->3’ helicase) of TFIIH,
XPG, XPC, XPF(a 5’-endonuclease), XPG (a 3’-endonuclease), DNA pol delta or
epsilon , PCNA, DNA-ligase are all important proteins in which DNA repair system?
Nucleotide Excision Repair (NER)
Describe this system...
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This test prep was uploaded on 03/23/2014 for the course CHEMISTRY 4141 taught by Professor Jonklaas during the Spring '13 term at Baylor.
- Spring '13