3H8I

The first X-ray structure of a sulfide:quinone oxidoreductase: Insights into sulfide oxidation mechanism

External Resource: Annotation

Domain Annotation: ECOD Classification
Domain Annotation: CATH
Protein Family Annotation
Gene Ontology: Gene Product Annotation
InterPro: Protein Family Classification
Structure Motif: Primary M-CSA Annotation

Domain Annotation: ECOD Classification ECOD Database Homepage

Chains	Family Name	Domain Identifier	Architecture	Possible Homology	Homology	Topology	Family	Provenance Source (Version)
A	Pyr_redox_2_2	e3h8iA2	A: a/b three-layered sandwiches	X: Rossmann-like	H: Rossmann-related	T: FAD/NAD(P)-binding domain	F: Pyr_redox_2_2	ECOD (1.6)
A	Pyr_redox_2	e3h8iA5	A: a/b three-layered sandwiches	X: Rossmann-like	H: Rossmann-related	T: FAD/NAD(P)-binding domain	F: Pyr_redox_2	ECOD (1.6)
B	Pyr_redox_2_2	e3h8iB2	A: a/b three-layered sandwiches	X: Rossmann-like	H: Rossmann-related	T: FAD/NAD(P)-binding domain	F: Pyr_redox_2_2	ECOD (1.6)
B	Pyr_redox_2	e3h8iB5	A: a/b three-layered sandwiches	X: Rossmann-like	H: Rossmann-related	T: FAD/NAD(P)-binding domain	F: Pyr_redox_2	ECOD (1.6)

Domain Annotation: CATH CATH Database Homepage

Chain	Domain	Class	Architecture	Topology	Homology	Provenance Source (Version)
A	3.50.50.60	Alpha Beta	3-Layer(bba) Sandwich	FAD/NAD(P)-binding domain	FAD/NAD(P)-binding domain	CATH (4.3.0)
B	3.50.50.60	Alpha Beta	3-Layer(bba) Sandwich	FAD/NAD(P)-binding domain	FAD/NAD(P)-binding domain	CATH (4.3.0)

Protein Family Annotation Pfam Database Homepage

Chains	Accession	Name	Description	Comments	Source
A, B	PF07992	Pyridine nucleotide-disulphide oxidoreductase (Pyr_redox_2)	Pyridine nucleotide-disulphide oxidoreductase	This family includes both class I and class II oxidoreductases and also NADH oxidases and peroxidases. This domain is actually a small NADH binding domain within a larger FAD binding domain.	Domain

Gene Ontology: Gene Product Annotation Gene Ontology Database Homepage

Chains	Polymer	Molecular Function	Biological Process	Cellular Component
A, B	NADH oxidase	oxidoreductase activity, acting on a sulfur group of donors oxidoreductase activity sulfide:quinone oxidoreductase activity catalytic activity oxidoreductase activity, acting on a sulfur group of donors, quinone or similar compound as acceptor binding nucleoside phosphate binding nucleotide binding heterocyclic compound binding small molecule binding quinone binding	-	cellular anatomical structure membrane

InterPro: Protein Family Classification InterPro Database Homepage

Chains	Accession	Name	Type
A, B	IPR052541	Sulfide-quinone oxidoreductase	Family
A, B	IPR023753	FAD/NAD(P)-binding domain	Domain
A, B	IPR036188	FAD/NAD(P)-binding domain superfamily	Homologous Superfamily

Structure Motif Annotation: Mechanism and Catalytic Site Atlas M-CSA Database Homepage

Chains	Enzyme Name	Description	Catalytic Residues
A	sulfide:quinone oxidoreductase M-CSA #320	Catalyses the oxidation of sulfides, such as hydrogen sulfide, with the help of a quinone to form sulfur globules. Consecutive reaction cycles lead to the accumulation of a polysulfide product on the active site Cys residues; these products are released when they exceed a critical length, typically as cyclooctasulfur. This is an important step in anoxygenic bacterial photosynthesis.	Defined by 6 residues: CYS:A-129CYS:A-178ASP:A-215CYS:A-350ASP:A-353LYS:A-386 Some residues are not modelled and lack atomic coordinates. Visualization is not available. Some residues are not modelled and lack atomic coordinates. Structure Motif searching is not available. EC: 1.6.99.3 (PDB Primary Data) EC: 1.8.5.4 (UniProt)

RCSB PDB Core Operations are funded by the U.S. National Science Foundation (DBI-2321666), the US Department of Energy (DE-SC0019749), and the National Cancer Institute, National Institute of Allergy and Infectious Diseases, and National Institute of General Medical Sciences of the National Institutes of Health under grant R01GM157729.