title: Dinucleotide spore photoproduct, a minimal substrate of the DNA repair spore photoproduct lyase enzyme from Bacillus subtilis.
abstract: The overwhelming majority of DNA photoproducts in UV-irradiated spores is a unique thymine dimer called spore photoproduct (SP, 5-thymine-5,6-dihydrothymine). This lesion is repaired by the spore photoproduct lyase (SP lyase) enzyme that directly reverts SP to two unmodified thymines. The SP lyase is an S-adenosylmethionine-dependent iron-sulfur protein that belongs to the radical S-adenosylmethionine superfamily. In this study, by using a well characterized preparation of the SP lyase enzyme from Bacillus subtilis, we show that SP in the form of a dinucleoside monophosphate (spore photoproduct of thymidilyl-(3'-5')-thymidine) is efficiently repaired, allowing a kinetic characterization of the enzyme. The preparation of this new substrate is described, and its identity is confirmed by mass spectrometry and comparison with authentic spore photoproduct. The fact that the spore photoproduct of thymidilyl-(3'-5')-thymidine dimer is repaired by SP lyase may indicate that the SP lesion does not absolutely need to be contained within a single- or double-stranded DNA for recognition and repaired by the SP lyase enzyme.
authors.affiliation: Laboratoire de Chimie et Biochimie des Centres Rédox Biologiques, DRDC-CB, UMR 5047, Commissariat à l'Energie Atomique/CNRS/Université Joseph Fourier, 17 Rue des Martyrs 38054, Grenoble Cedex 09, France.
authors.forename: Alexia
authors.initials: A
authors.lastname: Chandor
authors.forename: Olivier
authors.initials: O
authors.lastname: Berteau
authors.forename: Thierry
authors.initials: T
authors.lastname: Douki
authors.forename: Didier
authors.initials: D
authors.lastname: Gasparutto
authors.forename: Yannis
authors.initials: Y
authors.lastname: Sanakis
authors.forename: Sandrine
authors.initials: S
authors.lastname: Ollagnier-de-Choudens
authors.forename: Mohamed
authors.initials: M
authors.lastname: Atta
authors.forename: Marc
authors.initials: M
authors.lastname: Fontecave
mesh_terms: D001412:Bacillus subtilis / Q000201:enzymology*; D004260:DNA Repair; D004277:DNA, Single-Stranded / Q000737:chemistry; D004255:Deoxyribodipyrimidine Photo-Lyase / Q000737:chemistry*; D019281:Dimerization; D004578:Electron Spin Resonance Spectroscopy; D007700:Kinetics; D013058:Mass Spectrometry; D008956:Models, Chemical; D011506:Proteins / Q000737:chemistry*; D011740:Pyrimidine Dimers / Q000737:chemistry; D013379:Substrate Specificity; D013941:Thymine / Q000737:chemistry; D014466:Ultraviolet Rays
chemical_list: D004277:DNA, Single-Stranded; D011506:Proteins; D011740:Pyrimidine Dimers; C088014:spore photoproduct lyase; D004255:Deoxyribodipyrimidine Photo-Lyase; D013941:Thymine