DNA polymerase: Difference between revisions
From Proteopedia
Jump to navigationJump to search
Cori Damron (talk | contribs) No edit summary |
Cori Damron (talk | contribs) No edit summary |
||
| Line 121: | Line 121: | ||
The N-terminal of the Family Y polymerases contains the catalytic core of the fingers, palm, and thumb. The C-terminal, which has a conserved tertiary structure of a four-stranded beta sheet supported on one side by two alpha helices, otherwise referred to as the little finger domain, contributes to DNA binding and is essential for complete polymerase activity. This family lacks flexibility in the fingers subdomain, which is uncharacteristic of the other families. The other parts of the catalytic core and the little finger domain are flexible and frequently assume different positions. <ref>PMID: 20123134</ref> | The N-terminal of the Family Y polymerases contains the catalytic core of the fingers, palm, and thumb. The C-terminal, which has a conserved tertiary structure of a four-stranded beta sheet supported on one side by two alpha helices, otherwise referred to as the little finger domain, contributes to DNA binding and is essential for complete polymerase activity. This family lacks flexibility in the fingers subdomain, which is uncharacteristic of the other families. The other parts of the catalytic core and the little finger domain are flexible and frequently assume different positions. <ref>PMID: 20123134</ref> | ||
==Mechanism== | |||
The majority of DNA polymerases undergo a two-metal-ion mechanism. Two metal ions in the active site work to stabilize the pentacoordinated transition state. The first metal ion activates the hydroxyl groups. Those hydroxyl groups then go on to attack the phosphate group of the dNTP. The second metal ion not only stabilizes the negative charge, but also builds on the leaving oxygen and chelating phosphate groups. <ref> DOI: 10.1074/jbc.274.25.17395</ref> | |||
