5XMJ

Crystal structure of quinol:fumarate reductase from Desulfovibrio gigas

Summary for 5XMJ

• Entry DOI: 10.2210/pdb5xmj/pdb
• Descriptor: fumarate reductase flavoprotein subunit, DODECYL-BETA-D-MALTOSIDE, MENAQUINONE-7, ... (11 entities in total)
• Functional Keywords: membrane protein, electron transfer, qfr, proton transfer, electron transport
• Biological source: Desulfovibrio gigas; More
• Total number of polymer chains: 12
• Total formula weight: 506263.18

Authors

Guan, H.H.,Hsieh, Y.C.,Lin, P.R.,Chen, C.J. (deposition date: 2017-05-15, release date: 2018-06-06, Last modification date: 2023-11-22)

Primary citation

Guan, H.H.,Hsieh, Y.C.,Lin, P.J.,Huang, Y.C.,Yoshimura, M.,Chen, L.Y.,Chen, S.K.,Chuankhayan, P.,Lin, C.C.,Chen, N.C.,Nakagawa, A.,Chan, S.I.,Chen, C.J.
Structural insights into the electron/proton transfer pathways in the quinol:fumarate reductase from Desulfovibrio gigas.
Sci Rep, 8:14935-14935, 2018

PubMed Abstract: The membrane-embedded quinol:fumarate reductase (QFR) in anaerobic bacteria catalyzes the reduction of fumarate to succinate by quinol in the anaerobic respiratory chain. The electron/proton-transfer pathways in QFRs remain controversial. Here we report the crystal structure of QFR from the anaerobic sulphate-reducing bacterium Desulfovibrio gigas (D. gigas) at 3.6 Å resolution. The structure of the D. gigas QFR is a homo-dimer, each protomer comprising two hydrophilic subunits, A and B, and one transmembrane subunit C, together with six redox cofactors including two b-hemes. One menaquinone molecule is bound near heme b in the hydrophobic subunit C. This location of the menaquinone-binding site differs from the menaquinol-binding cavity proposed previously for QFR from Wolinella succinogenes. The observed bound menaquinone might serve as an additional redox cofactor to mediate the proton-coupled electron transport across the membrane. Armed with these structural insights, we propose electron/proton-transfer pathways in the quinol reduction of fumarate to succinate in the D. gigas QFR.

PubMed: 30297797
DOI: 10.1038/s41598-018-33193-5

Experimental method

X-RAY DIFFRACTION (3.6 Å)