1y97
From Proteopedia
(New page: 200px<br /> <applet load="1y97" size="450" color="white" frame="true" align="right" spinBox="true" caption="1y97, resolution 2.5Å" /> '''The human TREX2 3' e...) |
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| - | [[Image:1y97.gif|left|200px]]<br /> | + | [[Image:1y97.gif|left|200px]]<br /><applet load="1y97" size="350" color="white" frame="true" align="right" spinBox="true" |
| - | <applet load="1y97" size=" | + | |
caption="1y97, resolution 2.5Å" /> | caption="1y97, resolution 2.5Å" /> | ||
'''The human TREX2 3' exonuclease structure suggests a mechanism for efficient non-processive DNA catalysis'''<br /> | '''The human TREX2 3' exonuclease structure suggests a mechanism for efficient non-processive DNA catalysis'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The 3' --> 5'-exonucleases process DNA ends in many DNA repair pathways of | + | The 3' --> 5'-exonucleases process DNA ends in many DNA repair pathways of human cells. Determination of the human TREX2 structure is the first of a dimeric 3'-deoxyribonuclease and indicates how this highly efficient nonprocessive enzyme removes nucleotides at DNA 3' termini. Symmetry in the TREX2 dimer positions the active sites at opposite outer edges providing open access for the DNA. Adjacent to each active site is a flexible region containing three arginines positioned appropriately to bind DNA and to control its entry into the active site. Mutation of these three arginines to alanines reduces the DNA binding capacity by approximately 100-fold with no effect on catalysis. The human TREX2 catalytic residues overlay with the bacterial DnaQ family of 3'-exonucleases confirming the structural conservation of the catalytic sites despite limited sequence identity, and mutations of these residues decrease the still measurable activity by approximately 10(5)-fold, confirming their catalytic role. |
==About this Structure== | ==About this Structure== | ||
| - | 1Y97 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Active as [http://en.wikipedia.org/wiki/Exodeoxyribonuclease_III Exodeoxyribonuclease III], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.1.11.2 3.1.11.2] Full crystallographic information is available from [http:// | + | 1Y97 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Active as [http://en.wikipedia.org/wiki/Exodeoxyribonuclease_III Exodeoxyribonuclease III], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.1.11.2 3.1.11.2] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1Y97 OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Hollis, T.]] | [[Category: Hollis, T.]] | ||
[[Category: McMillin, S.]] | [[Category: McMillin, S.]] | ||
| - | [[Category: Perrino, F | + | [[Category: Perrino, F W.]] |
[[Category: exonuclease]] | [[Category: exonuclease]] | ||
[[Category: trex2]] | [[Category: trex2]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 16:02:59 2008'' |
Revision as of 14:03, 21 February 2008
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The human TREX2 3' exonuclease structure suggests a mechanism for efficient non-processive DNA catalysis
Overview
The 3' --> 5'-exonucleases process DNA ends in many DNA repair pathways of human cells. Determination of the human TREX2 structure is the first of a dimeric 3'-deoxyribonuclease and indicates how this highly efficient nonprocessive enzyme removes nucleotides at DNA 3' termini. Symmetry in the TREX2 dimer positions the active sites at opposite outer edges providing open access for the DNA. Adjacent to each active site is a flexible region containing three arginines positioned appropriately to bind DNA and to control its entry into the active site. Mutation of these three arginines to alanines reduces the DNA binding capacity by approximately 100-fold with no effect on catalysis. The human TREX2 catalytic residues overlay with the bacterial DnaQ family of 3'-exonucleases confirming the structural conservation of the catalytic sites despite limited sequence identity, and mutations of these residues decrease the still measurable activity by approximately 10(5)-fold, confirming their catalytic role.
About this Structure
1Y97 is a Single protein structure of sequence from Homo sapiens. Active as Exodeoxyribonuclease III, with EC number 3.1.11.2 Full crystallographic information is available from OCA.
Reference
The human TREX2 3' -> 5'-exonuclease structure suggests a mechanism for efficient nonprocessive DNA catalysis., Perrino FW, Harvey S, McMillin S, Hollis T, J Biol Chem. 2005 Apr 15;280(15):15212-8. Epub 2005 Jan 19. PMID:15661738
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