[FPG_LACLC] 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). 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.
The formamidopyrimidine-DNA glycosylase (Fpg, MutM) is a bifunctional base excision repair enzyme (DNA glycosylase/AP lyase) that removes a wide range of oxidized purines, such as 8-oxoguanine and imidazole ring-opened purines, from oxidatively damaged DNA. The structure of a non-covalent complex between the Lactoccocus lactis Fpg and a 1,3-propanediol (Pr) abasic site analogue-containing DNA has been solved. Through an asymmetric interaction along the damaged strand and the intercalation of the triad (M75/R109/F111), Fpg pushes out the Pr site from the DNA double helix, recognizing the cytosine opposite the lesion and inducing a 60 degrees bend of the DNA. The specific recognition of this cytosine provides some structural basis for understanding the divergence between Fpg and its structural homologue endo nuclease VIII towards their substrate specificities. In addition, the modelling of the 8-oxoguanine residue allows us to define an enzyme pocket that may accommodate the extrahelical oxidized base.
Crystal structure of the Lactococcus lactis formamidopyrimidine-DNA glycosylase bound to an abasic site analogue-containing DNA.,Serre L, Pereira de Jesus K, Boiteux S, Zelwer C, Castaing B EMBO J. 2002 Jun 17;21(12):2854-65. PMID:12065399
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
↑ Duwat P, de Oliveira R, Ehrlich SD, Boiteux S. Repair of oxidative DNA damage in gram-positive bacteria: the Lactococcus lactis Fpg protein. Microbiology. 1995 Feb;141 ( Pt 2):411-7. PMID:7704272
↑ Serre L, Pereira de Jesus K, Boiteux S, Zelwer C, Castaing B. Crystal structure of the Lactococcus lactis formamidopyrimidine-DNA glycosylase bound to an abasic site analogue-containing DNA. EMBO J. 2002 Jun 17;21(12):2854-65. PMID:12065399 doi:http://dx.doi.org/10.1093/emboj/cdf304