1q3b
Crystal structure of the DNA repair enzyme endonuclease-VIII (Nei) from E. coli: The R252A mutant at 2.05 resolution.
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OverviewOverview
Escherichia coli endonuclease VIII (Nei) excises oxidized pyrimidines from, DNA. It shares significant sequence homology and similar mechanism with, Fpg, a bacterial 8-oxoguanine glycosylase. The structure of a covalent, Nei-DNA complex has been recently determined, revealing critical amino, acid residues which are important for DNA binding and catalysis. Several, Fpg structures have also been reported; however, analysis of structural, dynamics of Fpg/Nei family proteins has been hindered by the lack of, structures of uncomplexed and DNA-bound enzymes from the same source. We, report a 2.8 A resolution structure of free wild-type Nei and two, structures of its inactive mutants, Nei-E2A (2.3 A) and Nei-R252A (2.05, A). All three structures are virtually identical, demonstrating that the, mutations did not affect the overall conformation of the protein in its, free state. The structures show a significant conformational change, compared with the Nei structure in its complex with DNA, reflecting a, approximately 50 degrees rotation of the two main domains of the enzyme., Such interdomain flexibility has not been reported previously for any DNA, glycosylase and may present the first evidence for a global DNA-induced, conformational change in this class of enzymes. Several local but, functionally relevant structural changes are also evident in other parts, of the enzyme.
About this StructureAbout this Structure
1Q3B is a Single protein structure of sequence from Escherichia coli with ZN, MG and GOL as ligands. Full crystallographic information is available from OCA.
ReferenceReference
Structure of the uncomplexed DNA repair enzyme endonuclease VIII indicates significant interdomain flexibility., Golan G, Zharkov DO, Feinberg H, Fernandes AS, Zaika EI, Kycia JH, Grollman AP, Shoham G, Nucleic Acids Res. 2005 Sep 6;33(15):5006-16. Print 2005. PMID:16145054
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