Studies on the Mechanism of Electron Bifurcation Catalyzed by Electron 
Transferring Flavoprotein (Etf) and Butyryl-CoA Dehydrogenase (Bcd) of 
Acidaminococcus fermentans

Chowdhury, Nilanjan Pal; Mowafy, Amr M.; Demmer, Julius K.; Upadhyay, Vikrant; Koelzer, Sebastian; Jayamani, Elamparithi; Kahnt, Joerg; Hornung, Marco; Demmer, Ulrike; Ermler, Ulrich; Buckel, Wolfgang

doi:10.1074/jbc.M113.521013

Item

ITEM ACTIONSEXPORT

Add to Basket

Local TagsRelease HistoryDetailsSummary

Released

Journal Article

Studies on the Mechanism of Electron Bifurcation Catalyzed by Electron Transferring Flavoprotein (Etf) and Butyryl-CoA Dehydrogenase (Bcd) of Acidaminococcus fermentans

MPS-Authors

Chowdhury, Nilanjan Pal
Laboratorium für Mikrobiologie, Fachbereich Biologie and SYNMIKRO, Philipps-Universität, 35032 Marburg, Germany;
Max-Planck-Institut für terrestrische Mikrobiologie, Karl-von-Frisch-Str. 10, 35043 Marburg, Max Planck Society, Germany;

Mowafy, Amr M.
Laboratorium für Mikrobiologie, Fachbereich Biologie and SYNMIKRO, Philipps-Universität, 35032 Marburg, Germany;
Max-Planck-Institut für terrestrische Mikrobiologie, Karl-von-Frisch-Str. 10, 35043 Marburg, Max Planck Society, Germany;

/persons/resource/persons146335

Demmer, Julius K.
Department of Molecular Membrane Biology, Max Planck Institute of Biophysics, Max Planck Society;
Max-Planck-Institut für terrestrische Mikrobiologie, Karl-von-Frisch-Str. 10, 35043 Marburg, Max Planck Society, Germany;

/persons/resource/persons137925

Upadhyay, Vikrant
Department of Molecular Membrane Biology, Max Planck Institute of Biophysics, Max Planck Society;

Jayamani, Elamparithi
Laboratorium für Mikrobiologie, Fachbereich Biologie and SYNMIKRO, Philipps-Universität, 35032 Marburg, Germany;
Max-Planck-Institut für terrestrische Mikrobiologie, Karl-von-Frisch-Str. 10, 35043 Marburg, Max Planck Society, Germany;

Kahnt, Joerg
Max-Planck-Institut für terrestrische Mikrobiologie, Karl-von-Frisch-Str. 10, 35043 Marburg, Max Planck Society, Germany;

Hornung, Marco
Laboratorium für Mikrobiologie, Fachbereich Biologie and SYNMIKRO, Philipps-Universität, 35032 Marburg, Germany;
Max-Planck-Institut für terrestrische Mikrobiologie, Karl-von-Frisch-Str. 10, 35043 Marburg, Max Planck Society, Germany;

/persons/resource/persons137633

Demmer, Ulrike
Department of Molecular Membrane Biology, Max Planck Institute of Biophysics, Max Planck Society;

/persons/resource/persons137648

Ermler, Ulrich
Department of Molecular Membrane Biology, Max Planck Institute of Biophysics, Max Planck Society;

Buckel, Wolfgang
Laboratorium für Mikrobiologie, Fachbereich Biologie and SYNMIKRO, Philipps-Universität, 35032 Marburg, Germany;
Max-Planck-Institut für terrestrische Mikrobiologie, Karl-von-Frisch-Str. 10, 35043 Marburg, Max Planck Society, Germany;

External Resource

No external resources are shared

Fulltext (restricted access)

There are currently no full texts shared for your IP range.

Fulltext (public)

There are no public fulltexts stored in PuRe

Supplementary Material (public)

There is no public supplementary material available

Citation

Chowdhury, N. P., Mowafy, A. M., Demmer, J. K., Upadhyay, V., Koelzer, S., Jayamani, E., et al. (2014). Studies on the Mechanism of Electron Bifurcation Catalyzed by Electron Transferring Flavoprotein (Etf) and Butyryl-CoA Dehydrogenase (Bcd) of Acidaminococcus fermentans. The Journal of Biological Chemistry, 289(8), 5145-5157. doi:10.1074/jbc.M113.521013.

Cite as: https://hdl.handle.net/11858/00-001M-0000-0026-B1AB-7

Abstract

Electron bifurcation is a fundamental strategy of energy coupling originally discovered in the Q-cycle of many organisms. Recently a flavin-based electron bifurcation has been detected in anaerobes, first in clostridia and later in acetogens and methanogens. It enables anaerobic bacteria and archaea to reduce the low-potential [4Fe-4S] clusters of ferredoxin, which increases the efficiency of the substrate level and electron transport phosphorylations. Here we characterize the bifurcating electron transferring flavoprotein (Etf_Af) and butyryl-CoA dehydrogenase (Bcd_Af) of Acidaminococcus fermentans, which couple the exergonic reduction of crotonyl-CoA to butyryl-CoA to the endergonic reduction of ferredoxin both with NADH. Etf_Af contains one FAD (α-FAD) in subunit α and a second FAD (β-FAD) in subunit β. The distance between the two isoalloxazine rings is 18 Å. The Etf_Af-NAD⁺ complex structure revealed β-FAD as acceptor of the hydride of NADH. The formed β-FADH^- is considered as the bifurcating electron donor. As a result of a domain movement, α-FAD is able to approach β-FADH^- by about 4 Å and to take up one electron yielding a stable anionic semiquinone, α-FAD^-, which donates this electron further to Dh-FAD of Bcd_Af after a second domain movement. The remaining nonstabilized neutral semiquinone, β-FADHˑ, immediately reduces ferredoxin. Repetition of this process affords a second reduced ferredoxin and Dh-FADH^- that converts crotonyl-CoA to butyryl-CoA.