Invited Speaker Australian & New Zealand Society of Magnetic Resonance Conference 2017

Developing A Structural Model of a P450-Ferredoxin Complex from Orientation-Selective Double Electron-Electron Resonance Spectroscopy (#28)

Jeffrey Harmer 1 2 , Alice Bowen 2 , Eachan O.D Johnson 3 , Francesco Mercuri 4 , Nicola J Hoskins 3 , Janet Lovett 2 , Ruihong Qiao 5 , Stephen G Bell 3 , Weihong Zhou 5 , Christiane Timmel 2 , Luet Lok Wong 2
  1. University of Queensland, St Lucia, Qld, Australia
  2. Centre for Applied Electron Spin Resonance, Department of Chemistry, University of Oxford, Inorganic Chemistry Laboratory, Oxford , UK
  3. Department of Chemistry, University of Oxford, Inorganic Chemistry Laboratory, South Parks Road, Oxford , UK
  4. Istituto per lo Studio dei Materiali Nanostrutturati via P. Gobetti 101, Bologna, Italy
  5. College of Life Sciences and The State Key Laboratory of Medicinal Chemical Biology, Nankai University, Tianjin

Class I cytochrome P450 enzymes (CYPs) receive two electrons sequentially from NAD(P)H via a cognate ferredoxin reductase and ferredoxin, and are responsible for tasks as diverse as mitochondrial vitamin D3 hydroxylation and bacterial antibiotic synthesis. The interaction of these Class I CYPs with their cognate ferredoxin is specific and the first electron-transfer step is rate limiting. In order to reconstitute the activity of diverse CYPs, structural characterization of CYP:ferredoxin complexes is necessary, but little structural information is available. We report a rigid-body model of such a complex (CYP199A2:HaPux) in frozen solution derived from distance and orientation restraints gathered by orientation-dependent double electron-electron resonance (DEER), an EPR technique.

  1. [1] Bowen, A. M., et al. Orientation-Selective DEER Using Rigid Spin Labels, Cofactors, Metals, and Clusters. In Structural Information from Spin-Labels and Intrinsic Paramagnetic Centres in the Biosciences. Editors: C. R. Timmel and J. R. Harmer. 2014, vol 152: 283-327. [2] Abdalla, J. A. B., et al. "Characterisation of the paramagnetic 2Fe-2S (+) centre in palustrisredoxin-B (PuxB) from Rhodopseudomonas palustris CGA009: g-matrix determination and spin coupling analysis." Physical Chemistry Chemical Physics 2012, 14(18): 6526-6537.