Annotations: 6EHQ

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

Chains	Domain Info	Class	Fold	Superfamily	Family	Domain	Species	Provenance Source (Version)
B [auth L]	d6ehql_	Multi-domain proteins (alpha and beta)	HydB/Nqo4-like	HydB/Nqo4-like	automated matches	automated matches	(Escherichia coli K-12 ) [TaxId: 83333 ],	SCOPe (2.08)
D [auth M]	d6ehqm_	Multi-domain proteins (alpha and beta)	HydB/Nqo4-like	HydB/Nqo4-like	automated matches	automated matches	(Escherichia coli K-12 ) [TaxId: 83333 ],	SCOPe (2.08)
A [auth S]	d6ehqs_	Multi-domain proteins (alpha and beta)	HydA/Nqo6-like	HydA/Nqo6-like	automated matches	automated matches	(Escherichia coli K-12 ) [TaxId: 83333 ],	SCOPe (2.08)
C [auth T]	d6ehqt_	Multi-domain proteins (alpha and beta)	HydA/Nqo6-like	HydA/Nqo6-like	automated matches	automated matches	(Escherichia coli K-12 ) [TaxId: 83333 ],	SCOPe (2.08)

Domain Annotation: ECOD Classification ECOD Database Homepage

Chains	Family Name	Domain Identifier	Architecture	Possible Homology	Homology	Topology	Family	Provenance Source (Version)
B [auth L]	NiFeSe_Hases_2nd	e6ehqL1	A: beta meanders	X: all-beta domain in nickel-iron hydrogenase large subunit (From Topology)	H: all-beta domain in nickel-iron hydrogenase large subunit (From Topology)	T: all-beta domain in nickel-iron hydrogenase large subunit	F: NiFeSe_Hases_2nd	ECOD (1.6)
B [auth L]	NiFeSe_Hases_1st	e6ehqL3	A: alpha complex topology	X: alpha-helical domain in nickel-iron hydrogenase, large subunit (From Topology)	H: alpha-helical domain in nickel-iron hydrogenase, large subunit (From Topology)	T: alpha-helical domain in nickel-iron hydrogenase, large subunit	F: NiFeSe_Hases_1st	ECOD (1.6)
B [auth L]	NiFeSe_Hases_3rd	e6ehqL2	A: a+b two layers	X: FAD-linked reductases, C-terminal domain-like	H: Ni-Fe binding domain in nickel-iron hydrogenase large subunit (From Topology)	T: Ni-Fe binding domain in nickel-iron hydrogenase large subunit	F: NiFeSe_Hases_3rd	ECOD (1.6)
B [auth L]	NiFeSe_Hases_3rd_1	e6ehqL4	A: a+b two layers	X: FAD-linked reductases, C-terminal domain-like	H: Ni-Fe binding domain in nickel-iron hydrogenase large subunit (From Topology)	T: Ni-Fe binding domain in nickel-iron hydrogenase large subunit	F: NiFeSe_Hases_3rd_1	ECOD (1.6)
D [auth M]	NiFeSe_Hases_2nd	e6ehqM1	A: beta meanders	X: all-beta domain in nickel-iron hydrogenase large subunit (From Topology)	H: all-beta domain in nickel-iron hydrogenase large subunit (From Topology)	T: all-beta domain in nickel-iron hydrogenase large subunit	F: NiFeSe_Hases_2nd	ECOD (1.6)
D [auth M]	NiFeSe_Hases_1st	e6ehqM3	A: alpha complex topology	X: alpha-helical domain in nickel-iron hydrogenase, large subunit (From Topology)	H: alpha-helical domain in nickel-iron hydrogenase, large subunit (From Topology)	T: alpha-helical domain in nickel-iron hydrogenase, large subunit	F: NiFeSe_Hases_1st	ECOD (1.6)
D [auth M]	NiFeSe_Hases_3rd	e6ehqM2	A: a+b two layers	X: FAD-linked reductases, C-terminal domain-like	H: Ni-Fe binding domain in nickel-iron hydrogenase large subunit (From Topology)	T: Ni-Fe binding domain in nickel-iron hydrogenase large subunit	F: NiFeSe_Hases_3rd	ECOD (1.6)
D [auth M]	NiFeSe_Hases_3rd_1	e6ehqM4	A: a+b two layers	X: FAD-linked reductases, C-terminal domain-like	H: Ni-Fe binding domain in nickel-iron hydrogenase large subunit (From Topology)	T: Ni-Fe binding domain in nickel-iron hydrogenase large subunit	F: NiFeSe_Hases_3rd_1	ECOD (1.6)
A [auth S]	Oxidored_q6	e6ehqS1	A: a/b three-layered sandwiches	X: Flavodoxin-like	H: Class I glutamine amidotransferase-like	T: CheY-like	F: Oxidored_q6	ECOD (1.6)
A [auth S]	NiFe_hyd_SSU_C	e6ehqS2	A: few secondary structure elements	X: Fe-S cluster-binding domain in nickel-iron hydrogenase small subunit (From Topology)	H: Fe-S cluster-binding domain in nickel-iron hydrogenase small subunit (From Topology)	T: Fe-S cluster-binding domain in nickel-iron hydrogenase small subunit	F: NiFe_hyd_SSU_C	ECOD (1.6)
C [auth T]	Oxidored_q6	e6ehqT1	A: a/b three-layered sandwiches	X: Flavodoxin-like	H: Class I glutamine amidotransferase-like	T: CheY-like	F: Oxidored_q6	ECOD (1.6)
C [auth T]	NiFe_hyd_SSU_C	e6ehqT2	A: few secondary structure elements	X: Fe-S cluster-binding domain in nickel-iron hydrogenase small subunit (From Topology)	H: Fe-S cluster-binding domain in nickel-iron hydrogenase small subunit (From Topology)	T: Fe-S cluster-binding domain in nickel-iron hydrogenase small subunit	F: NiFe_hyd_SSU_C	ECOD (1.6)

Domain Annotation: CATH CATH Database Homepage

Chain	Domain	Class	Architecture	Topology	Homology	Provenance Source (Version)
B [auth L]	1.10.645.10	Mainly Alpha	Orthogonal Bundle	Cytochrome-c3 Hydrogenase	chain B	CATH (4.3.0)
D [auth M]	1.10.645.10	Mainly Alpha	Orthogonal Bundle	Cytochrome-c3 Hydrogenase	chain B	CATH (4.3.0)
A [auth S]	3.40.50.700	Alpha Beta	3-Layer(aba) Sandwich	Rossmann fold	NADH:ubiquinone oxidoreductase-like, 20kDa subunit	CATH (4.3.0)
A [auth S]	4.10.480.10	Few Secondary Structures	Irregular	Cytochrome-c3 Hydrogenase	Chain A, domain 2	CATH (4.3.0)
C [auth T]	3.40.50.700	Alpha Beta	3-Layer(aba) Sandwich	Rossmann fold	NADH:ubiquinone oxidoreductase-like, 20kDa subunit	CATH (4.3.0)
C [auth T]	4.10.480.10	Few Secondary Structures	Irregular	Cytochrome-c3 Hydrogenase	Chain A, domain 2	CATH (4.3.0)

Protein Family Annotation Pfam Database Homepage

Chains	Accession	Name	Description	Comments	Source
B [auth L], D [auth M]	PF00374	Nickel-dependent hydrogenase (NiFeSe_Hases)	Nickel-dependent hydrogenase	-	Family
A [auth S], C [auth T]	PF14720	NiFe/NiFeSe hydrogenase small subunit C-terminal (NiFe_hyd_SSU_C)	NiFe/NiFeSe hydrogenase small subunit C-terminal	-	Family
A [auth S], C [auth T]	PF01058	NADH ubiquinone oxidoreductase, 20 Kd subunit (Oxidored_q6)	NADH ubiquinone oxidoreductase, 20 Kd subunit	-	Family

Gene Ontology: Gene Product Annotation Gene Ontology Database Homepage

Chains	Polymer	Molecular Function	Biological Process	Cellular Component
B [auth L], D [auth M]	Hydrogenase-2 large chain	hydrogenase (acceptor) activity oxidoreductase activity oxidoreductase activity, acting on hydrogen as donor catalytic activity cation binding transition metal ion binding ion binding binding nickel cation binding metal ion binding small molecule binding oxidoreductase activity, acting on hydrogen as donor, iron-sulfur protein as acceptor ferredoxin hydrogenase activity	-	cell periphery plasma membrane membrane cellular anatomical entity
A [auth S], C [auth T]	Hydrogenase-2 small chain	iron-sulfur cluster binding binding metal cluster binding small molecule binding oxidoreductase activity oxidoreductase activity, acting on hydrogen as donor, iron-sulfur protein as acceptor oxidoreductase activity, acting on hydrogen as donor ferredoxin hydrogenase activity catalytic activity 3 iron, 4 sulfur cluster binding hydrogenase (acceptor) activity 4 iron, 4 sulfur cluster binding electron transfer activity cation binding iron-sulfur cluster binding binding metal cluster binding small molecule binding oxidoreductase activity oxidoreductase activity, acting on hydrogen as donor, iron-sulfur protein as acceptor oxidoreductase activity, acting on hydrogen as donor ferredoxin hydrogenase activity catalytic activity 3 iron, 4 sulfur cluster binding hydrogenase (acceptor) activity 4 iron, 4 sulfur cluster binding electron transfer activity cation binding ion binding metal ion binding	cellular respiration energy derivation by oxidation of organic compounds cellular metabolic process metabolic process cellular process generation of precursor metabolites and energy anaerobic respiration	membrane cellular anatomical entity protein-containing complex catalytic complex oxidoreductase complex ferredoxin hydrogenase complex intracellular protein-containing complex [Ni-Fe] hydrogenase complex cell periphery plasma membrane periplasmic space

InterPro: Protein Family Classification InterPro Database Homepage

Chains	Accession	Name	Type
B [auth L], D [auth M]	IPR001501	Nickel-dependent hydrogenase, large subunit	Family
B [auth L], D [auth M]	IPR029014	[NiFe]-hydrogenase, large subunit	Homologous Superfamily
B [auth L], D [auth M]	IPR018194	Nickel-dependent hydrogenase, large subunit, nickel binding site	Binding Site
A [auth S], C [auth T]	IPR006311	Twin-arginine translocation pathway, signal sequence	Conserved Site
A [auth S], C [auth T]	IPR001821	[NiFe]-hydrogenase, small subunit	Family
A [auth S], C [auth T]	IPR027394	Cytochrome-c3 hydrogenase, C-terminal	Domain
A [auth S], C [auth T]	IPR006137	NADH:ubiquinone oxidoreductase-like, 20kDa subunit	Domain
A [auth S], C [auth T]	IPR037024	[NiFe]-hydrogenase, small subunit, N-terminal domain superfamily	Homologous Superfamily
A [auth S], C [auth T]	IPR019546	Twin-arginine translocation pathway, signal sequence, bacterial/archaeal	Conserved Site
A [auth S], C [auth T]	IPR037148	[NiFe]-hydrogenase, small subunit, C-terminal domain superfamily	Homologous Superfamily

RCSB PDB Core Operations are funded by the National Science Foundation (DBI-1832184), 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 R01GM133198.