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  • The EMBO Journal (2002) 21, 2854 - 2865
  • doi:10.1093/emboj/cdf304

Crystal structure of the Lactococcus lactis formamidopyrimidine-DNA glycosylase bound to an abasic site analogue-containing DNA

Laurence Serre1, Karine Pereira de Jésus2, Serge Boiteux3, Charles Zelwer2 and Bertrand Castaing2

  1. Institut de Biologie Structurale, CNRS-CEA, 41 av. Jules Horowitz, 38027 Grenoble cedex 01, France
  2. Centre de Biophysique Moléculaire UPR4301 affiliated to the University of Orléans, CNRS, rue Charles Sadron, 45071 Orléans cedex 02, France
  3. Laboratoire de Radiobiologie du DNA, UMR217, CNRS-CEA, Centre d'Etudes Nucléaires, BP6, 92265 Fontenay-Aux-Roses, France

Correspondence to:

Bertrand Castaing, E-mail: castaing@cnrs-orleans.fr

Received 21 February 2002; Accepted 24 April 2002; Revised 24 April 2002

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° 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.

  • Keywords:

    • AP site,
    • base excision repair,
    • crystal,
    • Endo VIII,
    • Fpg