5OL2

The electron transferring flavoprotein/butyryl-CoA dehydrogenase complex from Clostridium difficile

Summary for 5OL2

• Entry DOI: 10.2210/pdb5ol2/pdb
• Descriptor: Electron transfer flavoprotein large subunit, Electron transfer flavoprotein small subunit, Acyl-CoA dehydrogenase, ... (6 entities in total)
• Functional Keywords: flavin based electron bifurcation, bioenergetics, electron transferring flavoprotein, acyl-coa dehydrogenase, flavoprotein
• Biological source: Clostridioides difficile; More
• Total number of polymer chains: 6
• Total formula weight: 217082.37

Authors

Demmer, J.K.,Chowdhury, N.P.,Selmer, T.,Ermler, U.,Buckel, W. (deposition date: 2017-07-26, release date: 2017-11-29, Last modification date: 2025-10-01)

Primary citation

Demmer, J.K.,Pal Chowdhury, N.,Selmer, T.,Ermler, U.,Buckel, W.
The semiquinone swing in the bifurcating electron transferring flavoprotein/butyryl-CoA dehydrogenase complex from Clostridium difficile.
Nat Commun, 8:1577-1577, 2017

PubMed Abstract: 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) 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.

PubMed: 29146947
DOI: 10.1038/s41467-017-01746-3

Experimental method

X-RAY DIFFRACTION (3.1 Å)