DNA Polymerase I: Difference between revisions
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Pol I from the thermophilic bacterium ''Thermus aquaticus'' (''Taq'') is 51% identical in sequence with ''E. coli'' Pol I, although it lacks a 3' → 5' exonuclease function due to the absence of critical residues. The X-ray structure of the complete ''Taq'' Pol I (1taq), was also determined by Steitz<ref>PMID: 7792597</ref>. Here its C-terminal Klenow fragment portion is initially viewed as is that in the foregoing structure of Klenow·DNA and colored light green, whereas the N-terminal 5' → 3' exonuclease portion is colored in rainbow order from its N-terminus (''blue'') to its C-terminus (''red''). Note that there is only tenuous contact between the Klenow fragment and the 5' → 3' exonuclease. Hence, it is unclear how they coordinate their activities to yield a dsDNA molecule with a single nick. | Pol I from the thermophilic bacterium ''Thermus aquaticus'' (''Taq'') is 51% identical in sequence with ''E. coli'' Pol I, although it lacks a 3' → 5' exonuclease function due to the absence of critical residues. The X-ray structure of the complete ''Taq'' Pol I (1taq), was also determined by Steitz<ref>PMID: 7792597</ref>. Here its C-terminal Klenow fragment portion is initially viewed as is that in the foregoing structure of Klenow·DNA and colored light green, whereas the N-terminal 5' → 3' exonuclease portion is colored in rainbow order from its N-terminus (''blue'') to its C-terminus (''red''). Note that there is only tenuous contact between the Klenow fragment and the 5' → 3' exonuclease. Hence, it is unclear how they coordinate their activities to yield a dsDNA molecule with a single nick. | ||
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==Structures of Klentaq1 in its closed and open forms== | ==Structures of Klentaq1 in its closed and open forms== | ||