1y97
From Proteopedia
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| , resolution 2.5Å | |||||||
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| Ligands: | |||||||
| Gene: | TREX2 (Homo sapiens) | ||||||
| Activity: | Exodeoxyribonuclease III, with EC number 3.1.11.2 | ||||||
| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
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. 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
Page seeded by OCA on Mon Mar 31 01:00:24 2008
