6OI5

Crystal structure of human Sulfide Quinone Oxidoreductase

Summary for 6OI5

• Entry DOI: 10.2210/pdb6oi5/pdb
• Descriptor: Sulfide:quinone oxidoreductase, mitochondrial, FLAVIN-ADENINE DINUCLEOTIDE (3 entities in total)
• Functional Keywords: oxidoreductase
• Biological source: Homo sapiens (Human)
• Total number of polymer chains: 2
• Total formula weight: 95582.96

Authors

Banerjee, R.,Cho, U.S.,Kim, H.,Moon, S. (deposition date: 2019-04-08, release date: 2020-01-15, Last modification date: 2024-10-30)

Primary citation

Landry, A.P.,Moon, S.,Kim, H.,Yadav, P.K.,Guha, A.,Cho, U.S.,Banerjee, R.
A Catalytic Trisulfide in Human Sulfide Quinone Oxidoreductase Catalyzes Coenzyme A Persulfide Synthesis and Inhibits Butyrate Oxidation.
Cell Chem Biol, 26:1515-1525.e4, 2019

PubMed Abstract: Mitochondrial sulfide quinone oxidoreductase (SQR) catalyzes the oxidation of HS to glutathione persulfide with concomitant reduction of CoQ. We report herein that the promiscuous activity of human SQR supported the conversion of CoA to CoA-SSH (CoA-persulfide), a potent inhibitor of butyryl-CoA dehydrogenase, and revealed a molecular link between sulfide and butyrate metabolism, which are known to interact. Three different CoQ-bound crystal structures furnished insights into how diverse substrates access human SQR, and provided snapshots of the reaction coordinate. Unexpectedly, the active site cysteines in SQR are configured in a bridging trisulfide at the start and end of the catalytic cycle, and the presence of sulfane sulfur was confirmed biochemically. Importantly, our study leads to a mechanistic proposal for human SQR in which sulfide addition to the trisulfide cofactor eliminates Cys-SSH, forming an intense charge-transfer complex with flavin adenine dinucleotide, and Cys-SSH, which transfers sulfur to an external acceptor.

PubMed: 31591036
DOI: 10.1016/j.chembiol.2019.09.010

Experimental method

X-RAY DIFFRACTION (2.811 Å)