DNA polymerase: Difference between revisions
Cori Damron (talk | contribs) No edit summary |
Cori Damron (talk | contribs) No edit summary |
||
| Line 110: | Line 110: | ||
===Family A=== | ===Family A=== | ||
In addition to the basic structure of DNA polymerase, the Family A polymerases also have a 5'-3' exonuclease that is required for the removal of RNA primers from Okazaki fragments. Not all, but some Family A polymerases also a 3'-5' exonuclease that is responsible for proofreading the DNA. <ref>PMID: 16230118</ref> | In addition to the basic structure of DNA polymerase, the Family A polymerases also have a 5'-3' exonuclease that is required for the removal of RNA primers from Okazaki fragments. Not all, but some Family A polymerases also a 3'-5' exonuclease that is responsible for proofreading the DNA. <ref name="structure">PMID: 16230118</ref> | ||
===Family B=== | ===Family B=== | ||
In addition to the basic structure of DNA polymerase, the Family B polymerases contain an extremely active 3'-5' exonuclease that corrects errors in DNA replication. | In addition to the basic structure of DNA polymerase, the Family B polymerases contain an extremely active 3'-5' exonuclease that corrects errors in DNA replication. <ref name="structure" /> | ||
===Family X=== | ===Family X=== | ||
| Line 119: | Line 119: | ||
===Family Y=== | ===Family Y=== | ||
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. | 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> | ||