1k82 | pdb_00001k82
Crystal structure of E.coli formamidopyrimidine-DNA glycosylase (Fpg) covalently trapped with DNA
Structural highlights
FunctionFPG_ECOLI Involved in base excision repair of DNA damaged by oxidation or by mutagenic agents. Acts as DNA glycosylase that recognizes and removes damaged bases. Has a preference for oxidized purines, such as 7,8-dihydro-8-oxoguanine (8-oxoG) and its derivatives such as guanidinohydantoin:C and spiroiminodihydantoin:C, however it also acts on thymine glycol:G, 5,6-dihydrouracil:G and 5-hydroxyuracil:G. Has AP (apurinic/apyrimidinic) lyase activity and introduces nicks in the DNA strand. Cleaves the DNA backbone by beta-delta elimination to generate a single-strand break at the site of the removed base with both 3'- and 5'-phosphates. Cleaves ssDNA containing an AP site.[1] [2] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedFormamidopyrimidine-DNA glycosylase (Fpg) is a DNA repair enzyme that excises oxidized purines from damaged DNA. The Schiff base intermediate formed during this reaction between Escherichia coli Fpg and DNA was trapped by reduction with sodium borohydride, and the structure of the resulting covalently cross-linked complex was determined at a 2.1-A resolution. Fpg is a bilobal protein with a wide, positively charged DNA-binding groove. It possesses a conserved zinc finger and a helix-two turn-helix motif that participate in DNA binding. The absolutely conserved residues Lys-56, His-70, Asn-168, and Arg-258 form hydrogen bonds to the phosphodiester backbone of DNA, which is sharply kinked at the lesion site. Residues Met-73, Arg-109, and Phe-110 are inserted into the DNA helix, filling the void created by nucleotide eversion. A deep hydrophobic pocket in the active site is positioned to accommodate an everted base. Structural analysis of the Fpg-DNA complex reveals essential features of damage recognition and the catalytic mechanism of Fpg. Structure of formamidopyrimidine-DNA glycosylase covalently complexed to DNA.,Gilboa R, Zharkov DO, Golan G, Fernandes AS, Gerchman SE, Matz E, Kycia JH, Grollman AP, Shoham G J Biol Chem. 2002 May 31;277(22):19811-6. Epub 2002 Mar 23. PMID:11912217[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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