1taq
From Proteopedia
(New page: 200px<br /><applet load="1taq" size="450" color="white" frame="true" align="right" spinBox="true" caption="1taq, resolution 2.4Å" /> '''STRUCTURE OF TAQ DNA ...) |
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| - | [[Image:1taq.gif|left|200px]]<br /><applet load="1taq" size=" | + | [[Image:1taq.gif|left|200px]]<br /><applet load="1taq" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1taq, resolution 2.4Å" /> | caption="1taq, resolution 2.4Å" /> | ||
'''STRUCTURE OF TAQ DNA POLYMERASE'''<br /> | '''STRUCTURE OF TAQ DNA POLYMERASE'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The DNA polymerase from Thermus aquaticus (Taq polymerase), famous for its | + | The DNA polymerase from Thermus aquaticus (Taq polymerase), famous for its use in the polymerase chain reaction, is homologous to Escherichia coli DNA polymerase I (pol I) Like pol I, Taq polymerase has a domain at its amino terminus (residues 1-290) that has 5' nuclease activity and a domain at its carboxy terminus that catalyses the polymerase reaction. Unlike pol I, the intervening domain in Taq polymerase has lost the editing 3'-5' exonuclease activity. Although the structure of the Klenow fragment of pol I has been known for ten years, that of the intact pol I has proved more elusive. The structure of Taq polymerase determined here at 2.4 A resolution shows that the structures of the polymerase domains of the thermostable enzyme and of the Klenow fragment are nearly identical, whereas the catalytically critical carboxylate residues that bind two metal ions are missing from the remnants of the 3'-5' exonuclease active site of Taq polymerase. The first view of the 5' nuclease domain, responsible for excising the Okazaki RNA in lagging-strand DNA replication, shows a cluster of conserved divalent metal-ion-binding carboxylates at the bottom of a cleft. The location of this 5'-nuclease active site some 70 A from the polymerase active site in this crystal form highlights the unanswered question of how this domain works in concert with the polymerase domain to produce a duplex DNA product that contains only a nick. |
==About this Structure== | ==About this Structure== | ||
| - | 1TAQ is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Thermus_aquaticus Thermus aquaticus] with BGL and ZN as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/DNA-directed_DNA_polymerase DNA-directed DNA polymerase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.7.7.7 2.7.7.7] Full crystallographic information is available from [http:// | + | 1TAQ is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Thermus_aquaticus Thermus aquaticus] with <scene name='pdbligand=BGL:'>BGL</scene> and <scene name='pdbligand=ZN:'>ZN</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/DNA-directed_DNA_polymerase DNA-directed DNA polymerase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.7.7.7 2.7.7.7] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1TAQ OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Thermus aquaticus]] | [[Category: Thermus aquaticus]] | ||
| - | [[Category: Eom, S | + | [[Category: Eom, S H.]] |
[[Category: Kim, Y.]] | [[Category: Kim, Y.]] | ||
| - | [[Category: Lee, D | + | [[Category: Lee, D S.]] |
| - | [[Category: Steitz, T | + | [[Category: Steitz, T A.]] |
| - | [[Category: Suh, S | + | [[Category: Suh, S W.]] |
[[Category: Wang, J.]] | [[Category: Wang, J.]] | ||
[[Category: BGL]] | [[Category: BGL]] | ||
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[[Category: taq dna polymerase]] | [[Category: taq dna polymerase]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 15:11:43 2008'' |
Revision as of 13:11, 21 February 2008
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STRUCTURE OF TAQ DNA POLYMERASE
Overview
The DNA polymerase from Thermus aquaticus (Taq polymerase), famous for its use in the polymerase chain reaction, is homologous to Escherichia coli DNA polymerase I (pol I) Like pol I, Taq polymerase has a domain at its amino terminus (residues 1-290) that has 5' nuclease activity and a domain at its carboxy terminus that catalyses the polymerase reaction. Unlike pol I, the intervening domain in Taq polymerase has lost the editing 3'-5' exonuclease activity. Although the structure of the Klenow fragment of pol I has been known for ten years, that of the intact pol I has proved more elusive. The structure of Taq polymerase determined here at 2.4 A resolution shows that the structures of the polymerase domains of the thermostable enzyme and of the Klenow fragment are nearly identical, whereas the catalytically critical carboxylate residues that bind two metal ions are missing from the remnants of the 3'-5' exonuclease active site of Taq polymerase. The first view of the 5' nuclease domain, responsible for excising the Okazaki RNA in lagging-strand DNA replication, shows a cluster of conserved divalent metal-ion-binding carboxylates at the bottom of a cleft. The location of this 5'-nuclease active site some 70 A from the polymerase active site in this crystal form highlights the unanswered question of how this domain works in concert with the polymerase domain to produce a duplex DNA product that contains only a nick.
About this Structure
1TAQ is a Single protein structure of sequence from Thermus aquaticus with and as ligands. Active as DNA-directed DNA polymerase, with EC number 2.7.7.7 Full crystallographic information is available from OCA.
Reference
Crystal structure of Thermus aquaticus DNA polymerase., Kim Y, Eom SH, Wang J, Lee DS, Suh SW, Steitz TA, Nature. 1995 Aug 17;376(6541):612-6. PMID:7637814
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