title: Multifrequency EPR analysis of the dimanganese cluster of the putative sulfate thiohydrolase SoxB of Paracoccus pantotrophus.
abstract: A detailed analysis of the EPR signatures at X-band and Q-band of an enzyme (SoxB) involved in sulfur oxidation from Paracoccus pantotrophus is presented. EPR spectra are attributed to an exchange-coupled dimanganese Mn(2)(II,II) complex. An antiferromagnetic exchange interaction of J=-7.0 (+/-1) cm(-1) (H=-2JS ( 1 ) S ( 2 )) is evidenced by a careful examination of the temperature dependence of the EPR spectra. The spin Hamiltonian parameters for a total spin of S ( T ) =1, 2 and 3 are obtained and an inter-manganese distance of 3.4 (+/-0.1) A is estimated. The comparison with exchange coupling and inter-manganese distance data of other dimanganese proteins and model compounds leads to a tentative assignment of the Mn bridging ligands to bis(mu-hydroxo) (mu-carboxylato).
authors.affiliation: Max-Planck-Institut für Bioanorganische Chemi, Stiftstr. 34-36, 45470, Mülheim, Ruhr, Germany.
authors.forename: Boris
authors.initials: B
authors.lastname: Epel
authors.forename: Kai-Oliver
authors.initials: KO
authors.lastname: Schäfer
authors.forename: Armin
authors.initials: A
authors.lastname: Quentmeier
authors.forename: Cornelius
authors.initials: C
authors.lastname: Friedrich
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Lubitz
mesh_terms: D004578:Electron Spin Resonance Spectroscopy; D006867:Hydrolases / Q000737:chemistry*; D008345:Manganese / Q000737:chemistry*; D042084:Paracoccus pantotrophus / Q000201:enzymology*; D011487:Protein Conformation; D013431:Sulfates / Q000378:metabolism; D013455:Sulfur / Q000378:metabolism
chemical_list: D013431:Sulfates; D008345:Manganese; D013455:Sulfur; D006867:Hydrolases