Analysis of the magnetic properties of nitrogenase FeMo cofactor by single-crystal EPR spectroscopy.
The catalytic center of nitrogenase, the [Mo:7Fe:9S:C]:homocitrate FeMo cofactor, is a S=3/2 system with a rhombic magnetic g tensor. Single-crystal EPR spectroscopy in combination with X-ray diffraction were used to determine the relative orientation of the g tensor with respect to the cluster structure. The protein environment influences the electronic structure of the FeMo cofactor, dictating preferred orientations of possible functional relevance.
Institut für Biochemie, Albert-Ludwigs-Universität Freiburg, Albertstrasse 21, 79104 Freiburg (Germany) http://portal.uni-freiburg.de/biochemie; BIOSS Centre for Biological Signalling Studies, Hebelstrasse 25, 79104 Freiburg (Germany); Present address: Howard Hughes Medical Institute (HHMI) and Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 East California Boulevard, Pasadena CA 91125 (USA).
Thomas
T
Spatzal
Oliver
O
Einsle
Susana L A
SL
Andrade
D004578:Electron Spin Resonance Spectroscopy / Q000379:methods; D060328:Magnetic Phenomena; D008983:Molybdoferredoxin / Q000378:metabolism*; D009586:Nitrogen Fixation; D009591:Nitrogenase / Q000032:analysis / Q000378:metabolism*; D010084:Oxidation-Reduction
D008983:Molybdoferredoxin; D009591:Nitrogenase
EPR spectroscopy; FeMo cofactor; biological nitrogen fixation; g tensor; magnetic properties