title: The role of X-ray spectroscopy in understanding the geometric and electronic structure of nitrogenase.
abstract: X-ray absorption (XAS) and X-ray emission spectroscopy (XES) provide element specific probes of the geometric and electronic structures of metalloprotein active sites. As such, these methods have played an integral role in nitrogenase research beginning with the first EXAFS studies on nitrogenase in the late 1970s. Herein, we briefly explain the information that can be extracted from XAS and XES. We then highlight the recent applications of these methods in nitrogenase research. The influence of X-ray spectroscopy on our current understanding of the atomic structure and electronic structure of iron molybdenum cofactor (FeMoco) is emphasized. Contributions of X-ray spectroscopy to understanding substrate interactions and cluster biosynthesis are also discussed. This article is part of a Special Issue entitled: Fe/S proteins: Analysis, structure, function, biogenesis and diseases.
authors.affiliation: Max Planck Institute for Chemical Energy Conversion, Stiftstrasse 34-36, D-45470 Mülheim an der Ruhr, Germany.
authors.forename: Joanna
authors.initials: J
authors.lastname: Kowalska
authors.affiliation: Max Planck Institute for Chemical Energy Conversion, Stiftstrasse 34-36, D-45470 Mülheim an der Ruhr, Germany; Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY 14853, USA. Electronic address: serena.debeer@cec.mpg.de.
authors.forename: Serena
authors.initials: S
authors.lastname: DeBeer
mesh_terms: D003067:Coenzymes / Q000737:chemistry / Q000378:metabolism; D007501:Iron / Q000737:chemistry / Q000378:metabolism; D008667:Metalloproteins / Q000737:chemistry / Q000378:metabolism; D008958:Models, Molecular; D015394:Molecular Structure; D000090006:Molybdenum Cofactors; D009591:Nitrogenase / Q000737:chemistry* / Q000378:metabolism; D011487:Protein Conformation; D011621:Pteridines / Q000737:chemistry / Q000378:metabolism; D013052:Spectrometry, X-Ray Emission / Q000379:methods*; D056928:X-Ray Absorption Spectroscopy / Q000379:methods*
chemical_list: D003067:Coenzymes; D007501:Iron; D008667:Metalloproteins; D000090006:Molybdenum Cofactors; D009591:Nitrogenase; D011621:Pteridines; C022261:molybdopterin
keywords: Electronic structure; Nitrogenase; X-ray absorption spectroscopy; X-ray emission spectroscopy; XAS; XES