fingers Thumb incoming nucleotide Fingers template AT 3 5 5 bend in template primer template base Palm Figure 8-8 Copyright C 2004 Pearson Education, Inc publishiny as Del jalIl I Cullli l ys
Figure 8-8 Thumb Fingers Palm
DNA Polymerase-palm domain 1. Contains two catalytic sites, one for addition of dNTPs and one for removal of the mispaired dNTP 2. The polymerization site: (1)binds to two metal ions that alter the chemical environment around the catalytic site and lead to the catalysis (how? Figures 8-6,8-7)(2)Monitors the accuracy of base-pairing for the most recently added nucleotides by forming extensive hydrogen bond contacts with minor groove of the newly synthesized DNA 3. Exonuclease site/proof reading site See proofreading)
1. Contains two catalytic sites, one for addition of dNTPs and one for removal of the mispaired dNTP. 2. The polymerization site: (1) binds to two metal ions that alter the chemical environment around the catalytic site and lead to the catalysis. (how? Figures 8-6, 8-7). (2) Monitors the accuracy of base-pairing for the most recently added nucleotides by forming extensive hydrogen bond contacts with minor groove of the newly synthesized DNA. 3. Exonuclease site/proof reading site (See proofreading) DNA Polymerase-palm domain
O-helix ot Ohelix DNA polymerase sioni 3oH stalin A 人 Figure 8-6 Figure 8-7
Figure 8-6 Figure 8-7
DNA Polymerase-finger domain Binds to the incoming dNTP encloses the correct paired dNTP to the position for catalysis Bends the template to expose the only nucleotide at the template that ready for forming base pair with the incoming nucleotide Stabilization of the pyrophosphate
Binds to the incoming dNTP, encloses the correct paired dNTP to the position for catalysis Bends the template to expose the only nucleotide at the template that ready for forming base pair with the incoming nucleotide Stabilization of the pyrophosphate DNA Polymerase-finger domain
DNA Polymerase-thumb domain Not directly involved in catalysis Interacts with the synthesized dNA to maintain correct position of the primer and the active site, and to maintain a strong association between DNA Pol and its substrate
Not directly involved in catalysis Interacts with the synthesized DNA to maintain correct position of the primer and the active site, and to maintain a strong association between DNA Pol and its substrate. DNA Polymerase-thumb domain