• Deutsch
Login

Open Access

  • Home
  • Search
  • Browse
  • Publish
  • FAQ

Refine

Author

  • Ermler, Ulrich (2)
  • Bechtel, Dominique F. (1)
  • Boll, Matthias (1)
  • Buckel, Wolfgang (1)
  • Chowdhury, Nilanjan Pal (1)
  • Demmer, Julius Konstantin (1)
  • Demmer, Ulrike (1)
  • Heimann, Larissa (1)
  • Kayastha, Kanwal (1)
  • Müller, Christina S. (1)
+ more

Year of publication

  • 2017 (1)
  • 2019 (1)

Document Type

  • Article (2)

Language

  • English (2)

Has Fulltext

  • yes (2)

Is part of the Bibliography

  • no (2)

Keywords

  • Enzyme mechanisms (2) (remove)

Institute

  • MPI für Biophysik (2) (remove)

2 search hits

  • 1 to 2
  • 10
  • 20
  • 50
  • 100

Sort by

  • Year
  • Year
  • Title
  • Title
  • Author
  • Author
The semiquinone swing in the bifurcating electron transferring flavoprotein/butyryl-CoA dehydrogenase complex from Clostridium difficile (2017)
Demmer, Julius Konstantin ; Chowdhury, Nilanjan Pal ; Selmer, Thorsten ; Ermler, Ulrich ; Buckel, Wolfgang
The electron transferring flavoprotein/butyryl-CoA dehydrogenase (EtfAB/Bcd) catalyzes the reduction of one crotonyl-CoA and two ferredoxins by two NADH within a flavin-based electron-bifurcating process. Here we report on the X-ray structure of the Clostridium difficile (EtfAB/Bcd)4 complex in the dehydrogenase-conducting D-state, α-FAD (bound to domain II of EtfA) and δ-FAD (bound to Bcd) being 8 Å apart. Superimposing Acidaminococcus fermentans EtfAB onto C. difficile EtfAB/Bcd reveals a rotation of domain II of nearly 80°. Further rotation by 10° brings EtfAB into the bifurcating B-state, α-FAD and β-FAD (bound to EtfB) being 14 Å apart. This dual binding mode of domain II, substantiated by mutational studies, resembles findings in non-bifurcating EtfAB/acyl-CoA dehydrogenase complexes. In our proposed mechanism, NADH reduces β-FAD, which bifurcates. One electron goes to ferredoxin and one to α-FAD, which swings over to reduce δ-FAD to the semiquinone. Repetition affords a second reduced ferredoxin and δ-FADH−, which reduces crotonyl-CoA.
Low potential enzymatic hydride transfer via highly cooperative and inversely functionalized flavin cofactors (2019)
Willistein, Max ; Bechtel, Dominique F. ; Müller, Christina S. ; Demmer, Ulrike ; Heimann, Larissa ; Kayastha, Kanwal ; Schünemann, Volker ; Pierik, Antonio J. ; Ullmann, G. Matthias ; Ermler, Ulrich ; Boll, Matthias
Hydride transfers play a crucial role in a multitude of biological redox reactions and are mediated by flavin, deazaflavin or nicotinamide adenine dinucleotide cofactors at standard redox potentials ranging from 0 to –340 mV. 2-Naphthoyl-CoA reductase, a key enzyme of oxygen-independent bacterial naphthalene degradation, uses a low-potential one-electron donor for the two-electron dearomatization of its substrate below the redox limit of known biological hydride transfer processes at E°’ = −493 mV. Here we demonstrate by X-ray structural analyses, QM/MM computational studies, and multiple spectroscopy/activity based titrations that highly cooperative electron transfer (n = 3) from a low-potential one-electron (FAD) to a two-electron (FMN) transferring flavin cofactor is the key to overcome the resonance stabilized aromatic system by hydride transfer in a highly hydrophobic pocket. The results evidence how the protein environment inversely functionalizes two flavins to switch from low-potential one-electron to hydride transfer at the thermodynamic limit of flavin redox chemistry.
  • 1 to 2

OPUS4 Logo

  • Contact
  • Imprint
  • Sitelinks