title: Reversible inactivation of E. coli endonuclease III via modification of its [4Fe-4S] cluster by nitric oxide.
abstract: Endonuclease III, a highly conserved enzyme initiating the base excision repair of oxidized DNA bases, hosts a [4Fe-4S] cluster. Unlike many other iron-sulfur clusters, the [4Fe-4S] cluster of endonuclease III is stable and resistant to both oxidation and reduction. Here we show that the [4Fe-4S] cluster of the E. coli endonuclease III can be readily modified by nitric oxide forming the protein-bound dinitrosyl iron complex in vitro and in vivo. Modification of the [4Fe-4S] cluster completely inhibits the DNA glycosylase activity of the endonuclease III. Remarkably, the enzymatic activity is restored when the [4Fe-4S] cluster is re-assembled in the endonuclease III dinitrosyl iron complex with L-cysteine, cysteine desulfurase (IscS) and ferrous iron in vitro. Furthermore, the nitric oxide-modified [4Fe-4S] cluster in endonuclease III is efficiently repaired in aerobically growing E. coli cells, and this repair does not require new protein synthesis. These results suggest that the E. coli endonuclease III can be reversibly inactivated by nitric oxide via modification of its [4Fe-4S] cluster.
authors.affiliation: Department of Biological Sciences, 202 Life Sciences Building, Louisiana State University, Baton Rouge, LA , USA.
authors.forename: Paul A
authors.initials: PA
authors.lastname: Rogers
authors.forename: Lars
authors.initials: L
authors.lastname: Eide
authors.forename: Arne
authors.initials: A
authors.lastname: Klungland
authors.forename: Huangen
authors.initials: H
authors.lastname: Ding
mesh_terms: D013437:Carbon-Sulfur Lyases / Q000378:metabolism; D017931:DNA Primers; D004260:DNA Repair; D043224:Deoxyribonuclease (Pyrimidine Dimer) / Q000378:metabolism*; D004578:Electron Spin Resonance Spectroscopy; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics*; D029968:Escherichia coli Proteins / Q000378:metabolism*; D007501:Iron / Q000378:metabolism*; D009569:Nitric Oxide / Q000378:metabolism*; D009589:Nitrogen Oxides / Q000378:metabolism*; D013455:Sulfur / Q000378:metabolism
chemical_list: D017931:DNA Primers; D029968:Escherichia coli Proteins; D009589:Nitrogen Oxides; D009569:Nitric Oxide; C073661:dinitrosyl iron complex; D013455:Sulfur; D007501:Iron; D043224:Deoxyribonuclease (Pyrimidine Dimer); C106403:NTH protein, E coli; D013437:Carbon-Sulfur Lyases; C080546:cysteine desulfurase