3QEA

Crystal structure of human exonuclease 1 Exo1 (WT) in complex with DNA (complex II)

Summary for 3QEA

• Entry DOI: 10.2210/pdb3qea/pdb
• Related: 3QE9 3QEB
• Descriptor: Exonuclease 1, DNA (5'-D(P*CP*GP*CP*TP*AP*GP*TP*CP*GP*AP*CP*AP*T)-3'), DNA (5'-D(P*TP*CP*GP*AP*CP*TP*AP*GP*CP*G)-3'), ... (5 entities in total)
• Functional Keywords: exonuclease, hydrolase-dna complex, hydrolase/dna
• Biological source: Homo sapiens (human)
• Cellular location: Nucleus: Q9UQ84
• Total number of polymer chains: 3
• Total formula weight: 47105.81

Authors

Orans, J.,McSweeney, E.A.,Iyer, R.R.,Hast, M.A.,Hellinga, H.W.,Modrich, P.,Beese, L.S. (deposition date: 2011-01-20, release date: 2011-04-20, Last modification date: 2024-02-21)

Primary citation

Orans, J.,McSweeney, E.A.,Iyer, R.R.,Hast, M.A.,Hellinga, H.W.,Modrich, P.,Beese, L.S.
Structures of human exonuclease 1 DNA complexes suggest a unified mechanism for nuclease family.
Cell(Cambridge,Mass.), 145:212-223, 2011

PubMed Abstract: Human exonuclease 1 (hExo1) plays important roles in DNA repair and recombination processes that maintain genomic integrity. It is a member of the 5' structure-specific nuclease family of exonucleases and endonucleases that includes FEN-1, XPG, and GEN1. We present structures of hExo1 in complex with a DNA substrate, followed by mutagenesis studies, and propose a common mechanism by which this nuclease family recognizes and processes diverse DNA structures. hExo1 induces a sharp bend in the DNA at nicks or gaps. Frayed 5' ends of nicked duplexes resemble flap junctions, unifying the mechanisms of endo- and exonucleolytic processing. Conformational control of a mobile region in the catalytic site suggests a mechanism for allosteric regulation by binding to protein partners. The relative arrangement of substrate binding sites in these enzymes provides an elegant solution to a complex geometrical puzzle of substrate recognition and processing.

PubMed: 21496642
DOI: 10.1016/j.cell.2011.03.005

Experimental method

X-RAY DIFFRACTION (3.1 Å)