Annotations: 1SOX

Domain Annotation: SCOP/SCOPe Classification SCOP-e Database Homepage

Chains	Domain Info	Class	Fold	Superfamily	Family	Domain	Species	Provenance Source (Version)
A	d1soxa1	All beta proteins	Immunoglobulin-like beta-sandwich	E set domains	Molybdenum-containing oxidoreductases-like dimerisation domain	Sulfite oxidase, C-terminal domain	(Gallus gallus ) [TaxId: 9031 ],	SCOPe (2.08)
A	d1soxa2	Alpha and beta proteins (a+b)	Cytochrome b5-like heme/steroid binding domain	Cytochrome b5-like heme/steroid binding domain	Cytochrome b5	Sulfite oxidase, N-terminal domain	(Gallus gallus ) [TaxId: 9031 ],	SCOPe (2.08)
A	d1soxa3	Alpha and beta proteins (a+b)	Oxidoreductase molybdopterin-binding domain	Oxidoreductase molybdopterin-binding domain	Oxidoreductase molybdopterin-binding domain	Sulfite oxidase, middle catalytic domain	(Gallus gallus ) [TaxId: 9031 ],	SCOPe (2.08)
B	d1soxb1	All beta proteins	Immunoglobulin-like beta-sandwich	E set domains	Molybdenum-containing oxidoreductases-like dimerisation domain	Sulfite oxidase, C-terminal domain	(Gallus gallus ) [TaxId: 9031 ],	SCOPe (2.08)
B	d1soxb2	Alpha and beta proteins (a+b)	Cytochrome b5-like heme/steroid binding domain	Cytochrome b5-like heme/steroid binding domain	Cytochrome b5	Sulfite oxidase, N-terminal domain	(Gallus gallus ) [TaxId: 9031 ],	SCOPe (2.08)
B	d1soxb3	Alpha and beta proteins (a+b)	Oxidoreductase molybdopterin-binding domain	Oxidoreductase molybdopterin-binding domain	Oxidoreductase molybdopterin-binding domain	Sulfite oxidase, middle catalytic domain	(Gallus gallus ) [TaxId: 9031 ],	SCOPe (2.08)

Domain Annotation: SCOP2 Classification SCOP2 Database Homepage

Chains	Type	Family Name	Domain Identifier	Family Identifier	Provenance Source (Version)
A	SCOP2 Family	Cytochrome b5	8023816	4000144	SCOP2 (2022-06-29)
A	SCOP2 Superfamily	Cytochrome b5-like heme/steroid binding domain	8036196	3000073	SCOP2 (2022-06-29)
A	SCOP2B Superfamily	Oxidoreductase molybdopterin-binding domain	8036767	3001433	SCOP2B (2022-06-29)
A	SCOP2B Superfamily	E set domains	8055003	3000070	SCOP2B (2022-06-29)
B	SCOP2B Superfamily	Oxidoreductase molybdopterin-binding domain	8036767	3001433	SCOP2B (2022-06-29)
B	SCOP2B Superfamily	E set domains	8055003	3000070	SCOP2B (2022-06-29)
B	SCOP2B Superfamily	Cytochrome b5-like heme/steroid binding domain	8036196	3000073	SCOP2B (2022-06-29)

Domain Annotation: ECOD Classification ECOD Database Homepage

Chains	Family Name	Domain Identifier	Architecture	Possible Homology	Homology	Topology	Family	Provenance Source (Version)
A	PF03404	e1soxA1	A: beta sandwiches	X: Immunoglobulin-like beta-sandwich	H: Immunoglobulin-related	T: Immunoglobulin/Fibronectin type III/E set domains/PapD-like	F: PF03404	ECOD (1.6)
A	PF00174	e1soxA2	A: a+b two layers	X: beta-Grasp	H: Ubiquitin-related	T: Sulfite oxidase, middle catalytic domain	F: PF00174	ECOD (1.6)
A	PF00173	e1soxA3	A: a+b two layers	X: Cystatin-like	H: Cytochrome b5-like heme/steroid binding domain (From Topology)	T: Cytochrome b5-like heme/steroid binding domain	F: PF00173	ECOD (1.6)
B	PF03404	e1soxB1	A: beta sandwiches	X: Immunoglobulin-like beta-sandwich	H: Immunoglobulin-related	T: Immunoglobulin/Fibronectin type III/E set domains/PapD-like	F: PF03404	ECOD (1.6)
B	PF00174	e1soxB2	A: a+b two layers	X: beta-Grasp	H: Ubiquitin-related	T: Sulfite oxidase, middle catalytic domain	F: PF00174	ECOD (1.6)
B	PF00173	e1soxB3	A: a+b two layers	X: Cystatin-like	H: Cytochrome b5-like heme/steroid binding domain (From Topology)	T: Cytochrome b5-like heme/steroid binding domain	F: PF00173	ECOD (1.6)

Domain Annotation: CATH CATH Database Homepage

Chain	Domain	Class	Architecture	Topology	Homology	Provenance Source (Version)
A	3.10.120.10	Alpha Beta	Roll	Flavocytochrome B2	Chain A, domain 1	CATH (4.3.0)
A	3.90.420.10	Alpha Beta	Alpha-Beta Complex	Sulfite Oxidase	Chain A, domain 2	CATH (4.3.0)
A	2.60.40.650	Mainly Beta	Sandwich	Immunoglobulin-like		CATH (4.3.0)
B	3.10.120.10	Alpha Beta	Roll	Flavocytochrome B2	Chain A, domain 1	CATH (4.3.0)
B	3.90.420.10	Alpha Beta	Alpha-Beta Complex	Sulfite Oxidase	Chain A, domain 2	CATH (4.3.0)
B	2.60.40.650	Mainly Beta	Sandwich	Immunoglobulin-like		CATH (4.3.0)

Protein Family Annotation Pfam Database Homepage

Chains	Accession	Name	Description	Comments	Source
A, B	PF00173	Cytochrome b5-like Heme/Steroid binding domain (Cyt-b5)	Cytochrome b5-like Heme/Steroid binding domain	This family includes heme binding domains from a diverse range of proteins. This family also includes proteins that bind to steroids. The family includes progesterone receptors such as Swiss:O00264 [1,2]. Many members of this subfamily are membrane a ...	This family includes heme binding domains from a diverse range of proteins. This family also includes proteins that bind to steroids. The family includes progesterone receptors such as Swiss:O00264 [1,2]. Many members of this subfamily are membrane anchored by an N-terminal transmembrane alpha helix. This family also includes a domain in some chitin synthases. There is no known ligand for this domain in the chitin synthases.	Domain
A, B	PF00174	Oxidoreductase molybdopterin binding domain (Oxidored_molyb)	Oxidoreductase molybdopterin binding domain	This domain is found in a variety of oxidoreductases. This domain binds to a molybdopterin cofactor. Xanthine dehydrogenases, that also bind molybdopterin, have essentially no similarity.	Domain
A, B	PF03404	Mo-co oxidoreductase dimerisation domain (Mo-co_dimer)	Mo-co oxidoreductase dimerisation domain	This domain is found in molybdopterin cofactor (Mo-co) oxidoreductases. It is involved in dimer formation, and has an Ig-fold structure [1].	Domain

Gene Ontology: Gene Product Annotation Gene Ontology Database Homepage

Chains	Polymer	Molecular Function	Biological Process	Cellular Component
A, B	SULFITE OXIDASE	binding organic cyclic compound binding tetrapyrrole binding heme binding cation binding transition metal ion binding molybdenum ion binding ion binding metal ion binding small molecule binding oxidoreductase activity, acting on a sulfur group of donors oxidoreductase activity sulfite oxidase activity oxidoreductase activity, acting on a sulfur group of donors, oxygen as acceptor binding organic cyclic compound binding tetrapyrrole binding heme binding cation binding transition metal ion binding molybdenum ion binding ion binding metal ion binding small molecule binding oxidoreductase activity, acting on a sulfur group of donors oxidoreductase activity sulfite oxidase activity oxidoreductase activity, acting on a sulfur group of donors, oxygen as acceptor catalytic activity molybdopterin cofactor binding	cellular metabolic process sulfur compound metabolic process metabolic process cellular process	membrane-bounded organelle intracellular organelle intracellular anatomical structure mitochondrion organelle cytoplasm cellular anatomical entity intracellular membrane-bounded organelle mitochondrial intermembrane space membrane-enclosed lumen intracellular organelle lumen organelle envelope lumen organelle envelope organelle lumen membrane-bounded organelle intracellular organelle intracellular anatomical structure mitochondrion organelle cytoplasm cellular anatomical entity intracellular membrane-bounded organelle mitochondrial intermembrane space membrane-enclosed lumen intracellular organelle lumen organelle envelope lumen organelle envelope organelle lumen mitochondrial envelope

InterPro: Protein Family Classification InterPro Database Homepage

Chains	Accession	Name	Type
A, B	IPR036400	Cytochrome b5-like heme/steroid binding domain superfamily	Homologous Superfamily
A, B	IPR018506	Cytochrome b5, heme-binding site	Binding Site
A, B	IPR005066	Moybdenum cofactor oxidoreductase, dimerisation	Domain
A, B	IPR008335	Eukaryotic molybdopterin oxidoreductase	Family
A, B	IPR022407	Oxidoreductase, molybdopterin binding site	Binding Site
A, B	IPR036374	Oxidoreductase, molybdopterin-binding domain superfamily	Homologous Superfamily
A, B	IPR000572	Oxidoreductase, molybdopterin-binding domain	Domain
A, B	IPR014756	Immunoglobulin E-set	Homologous Superfamily
A, B	IPR001199	Cytochrome b5-like heme/steroid binding domain	Domain

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

Chains	Enzyme Name	Description	Catalytic Residues
A	sulfite oxidase M-CSA #121	Sulfite oxidase (SO) catalyses the terminal reaction in the oxidative degradation of the sulfur-containing amino acids cysteine and methionine specifically the oxidation of sulfite to sulfate by the transfer of an oxygen to the lone pair of electrons on the substrate. It is a member of the molybdopterin oxidoreductase family of proteins that contain a single pterin cofactor ligated to Mo(VI) and two oxo ligands. SO also contains a heme b molecule which is part of the electron transfer pathway from the molybdenum centre to the final electron acceptor (in this case ferrocytochrome c).	Defined by 5 residues: HIS:A-40HIS:A-65ARG:A-138CYS:A-185TYR:A-322 \| Explore in 3D: M-CSA Motif Definition Extent of motif is too large to support Structure Motif searching. EC: 1.8.3.1 (PDB Primary Data)

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