7SFV | pdb_00007sfv

CryoEM structure of Venezuelan Equine Encephalitis virus (VEEV) TC-83 strain VLP in complex with Fab hVEEV-63

External Resource: Annotation

Domain Annotation: SCOP2 Classification
Domain Annotation: ECOD Classification
Domain Annotation: CATH
SAbDab Antibody Annotation
Protein Family Annotation
Gene Ontology: Gene Product Annotation
InterPro: Protein Family Classification

Domain Annotation: SCOP2 Classification SCOP2 Database Homepage

Chains	Type	Family Name	Domain Identifier	Family Identifier	Provenance Source (Version)
L	SCOP2B Superfamily	Trypsin-like serine proteases	8044424	3000114	SCOP2B (2022-06-29)
I	SCOP2B Superfamily	Trypsin-like serine proteases	8044424	3000114	SCOP2B (2022-06-29)
F	SCOP2B Superfamily	Trypsin-like serine proteases	8044424	3000114	SCOP2B (2022-06-29)
C	SCOP2B Superfamily	Trypsin-like serine proteases	8044424	3000114	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)
T	C1-set	e7sfvT1	A: beta sandwiches	X: Immunoglobulin-like beta-sandwich	H: Immunoglobulin-related	T: Immunoglobulin/Fibronectin type III/E set domains/PapD-like	F: C1-set	ECOD (1.6)
T	V-set_3	e7sfvT2	A: beta sandwiches	X: Immunoglobulin-like beta-sandwich	H: Immunoglobulin-related	T: Immunoglobulin/Fibronectin type III/E set domains/PapD-like	F: V-set_3	ECOD (1.6)
R	C1-set	e7sfvR1	A: beta sandwiches	X: Immunoglobulin-like beta-sandwich	H: Immunoglobulin-related	T: Immunoglobulin/Fibronectin type III/E set domains/PapD-like	F: C1-set	ECOD (1.6)
R	V-set_3	e7sfvR2	A: beta sandwiches	X: Immunoglobulin-like beta-sandwich	H: Immunoglobulin-related	T: Immunoglobulin/Fibronectin type III/E set domains/PapD-like	F: V-set_3	ECOD (1.6)
P	C1-set	e7sfvP2	A: beta sandwiches	X: Immunoglobulin-like beta-sandwich	H: Immunoglobulin-related	T: Immunoglobulin/Fibronectin type III/E set domains/PapD-like	F: C1-set	ECOD (1.6)
P	V-set_3	e7sfvP1	A: beta sandwiches	X: Immunoglobulin-like beta-sandwich	H: Immunoglobulin-related	T: Immunoglobulin/Fibronectin type III/E set domains/PapD-like	F: V-set_3	ECOD (1.6)
N	C1-set	e7sfvN1	A: beta sandwiches	X: Immunoglobulin-like beta-sandwich	H: Immunoglobulin-related	T: Immunoglobulin/Fibronectin type III/E set domains/PapD-like	F: C1-set	ECOD (1.6)
N	V-set_3	e7sfvN2	A: beta sandwiches	X: Immunoglobulin-like beta-sandwich	H: Immunoglobulin-related	T: Immunoglobulin/Fibronectin type III/E set domains/PapD-like	F: V-set_3	ECOD (1.6)
S	V-set_8	e7sfvS2	A: beta sandwiches	X: Immunoglobulin-like beta-sandwich	H: Immunoglobulin-related	T: Immunoglobulin/Fibronectin type III/E set domains/PapD-like	F: V-set_8	ECOD (1.6)
S	C1-set_1	e7sfvS1	A: beta sandwiches	X: Immunoglobulin-like beta-sandwich	H: Immunoglobulin-related	T: Immunoglobulin/Fibronectin type III/E set domains/PapD-like	F: C1-set_1	ECOD (1.6)
Q	V-set_8	e7sfvQ1	A: beta sandwiches	X: Immunoglobulin-like beta-sandwich	H: Immunoglobulin-related	T: Immunoglobulin/Fibronectin type III/E set domains/PapD-like	F: V-set_8	ECOD (1.6)
Q	C1-set_1	e7sfvQ2	A: beta sandwiches	X: Immunoglobulin-like beta-sandwich	H: Immunoglobulin-related	T: Immunoglobulin/Fibronectin type III/E set domains/PapD-like	F: C1-set_1	ECOD (1.6)
O	V-set_8	e7sfvO2	A: beta sandwiches	X: Immunoglobulin-like beta-sandwich	H: Immunoglobulin-related	T: Immunoglobulin/Fibronectin type III/E set domains/PapD-like	F: V-set_8	ECOD (1.6)
O	C1-set_1	e7sfvO1	A: beta sandwiches	X: Immunoglobulin-like beta-sandwich	H: Immunoglobulin-related	T: Immunoglobulin/Fibronectin type III/E set domains/PapD-like	F: C1-set_1	ECOD (1.6)
M	V-set_8	e7sfvM1	A: beta sandwiches	X: Immunoglobulin-like beta-sandwich	H: Immunoglobulin-related	T: Immunoglobulin/Fibronectin type III/E set domains/PapD-like	F: V-set_8	ECOD (1.6)
M	C1-set_1	e7sfvM2	A: beta sandwiches	X: Immunoglobulin-like beta-sandwich	H: Immunoglobulin-related	T: Immunoglobulin/Fibronectin type III/E set domains/PapD-like	F: C1-set_1	ECOD (1.6)
L	Peptidase_S3	e7sfvL1	A: beta barrels	X: cradle loop barrel	H: RIFT-related	T: FMN-binding split barrel	F: Peptidase_S3	ECOD (1.6)
I	Peptidase_S3	e7sfvI1	A: beta barrels	X: cradle loop barrel	H: RIFT-related	T: FMN-binding split barrel	F: Peptidase_S3	ECOD (1.6)
F	Peptidase_S3	e7sfvF1	A: beta barrels	X: cradle loop barrel	H: RIFT-related	T: FMN-binding split barrel	F: Peptidase_S3	ECOD (1.6)
C	Peptidase_S3	e7sfvC1	A: beta barrels	X: cradle loop barrel	H: RIFT-related	T: FMN-binding split barrel	F: Peptidase_S3	ECOD (1.6)
J	Alpha_E1_glycop_2nd	e7sfvJ2	A: beta sandwiches	X: Immunoglobulin-like beta-sandwich	H: Immunoglobulin-related	T: Immunoglobulin/Fibronectin type III/E set domains/PapD-like	F: Alpha_E1_glycop_2nd	ECOD (1.6)
J	Alpha_E1_glycop_1st	e7sfvJ1	A: beta complex topology	X: Viral glycoprotein, central and dimerisation domains-like	H: Viral glycoprotein, central and dimerisation domains (From Topology)	T: Viral glycoprotein, central and dimerisation domains	F: Alpha_E1_glycop_1st	ECOD (1.6)
J	Alpha_E1_glycop_like	e7sfvJ3	A: extended segments	X: Transmembrane helix of E1 envelope glycoprotein (From Topology)	H: Transmembrane helix of E1 envelope glycoprotein (From Topology)	T: Transmembrane helix of E1 envelope glycoprotein	F: Alpha_E1_glycop_like	ECOD (1.6)
G	Alpha_E1_glycop_2nd	e7sfvG2	A: beta sandwiches	X: Immunoglobulin-like beta-sandwich	H: Immunoglobulin-related	T: Immunoglobulin/Fibronectin type III/E set domains/PapD-like	F: Alpha_E1_glycop_2nd	ECOD (1.6)
G	Alpha_E1_glycop_1st	e7sfvG1	A: beta complex topology	X: Viral glycoprotein, central and dimerisation domains-like	H: Viral glycoprotein, central and dimerisation domains (From Topology)	T: Viral glycoprotein, central and dimerisation domains	F: Alpha_E1_glycop_1st	ECOD (1.6)
G	Alpha_E1_glycop_like	e7sfvG3	A: extended segments	X: Transmembrane helix of E1 envelope glycoprotein (From Topology)	H: Transmembrane helix of E1 envelope glycoprotein (From Topology)	T: Transmembrane helix of E1 envelope glycoprotein	F: Alpha_E1_glycop_like	ECOD (1.6)
D	Alpha_E1_glycop_2nd	e7sfvD3	A: beta sandwiches	X: Immunoglobulin-like beta-sandwich	H: Immunoglobulin-related	T: Immunoglobulin/Fibronectin type III/E set domains/PapD-like	F: Alpha_E1_glycop_2nd	ECOD (1.6)
D	Alpha_E1_glycop_1st	e7sfvD1	A: beta complex topology	X: Viral glycoprotein, central and dimerisation domains-like	H: Viral glycoprotein, central and dimerisation domains (From Topology)	T: Viral glycoprotein, central and dimerisation domains	F: Alpha_E1_glycop_1st	ECOD (1.6)
D	Alpha_E1_glycop_like	e7sfvD2	A: extended segments	X: Transmembrane helix of E1 envelope glycoprotein (From Topology)	H: Transmembrane helix of E1 envelope glycoprotein (From Topology)	T: Transmembrane helix of E1 envelope glycoprotein	F: Alpha_E1_glycop_like	ECOD (1.6)
A	Alpha_E1_glycop_2nd	e7sfvA3	A: beta sandwiches	X: Immunoglobulin-like beta-sandwich	H: Immunoglobulin-related	T: Immunoglobulin/Fibronectin type III/E set domains/PapD-like	F: Alpha_E1_glycop_2nd	ECOD (1.6)
A	Alpha_E1_glycop_1st	e7sfvA1	A: beta complex topology	X: Viral glycoprotein, central and dimerisation domains-like	H: Viral glycoprotein, central and dimerisation domains (From Topology)	T: Viral glycoprotein, central and dimerisation domains	F: Alpha_E1_glycop_1st	ECOD (1.6)
A	Alpha_E1_glycop_like	e7sfvA2	A: extended segments	X: Transmembrane helix of E1 envelope glycoprotein (From Topology)	H: Transmembrane helix of E1 envelope glycoprotein (From Topology)	T: Transmembrane helix of E1 envelope glycoprotein	F: Alpha_E1_glycop_like	ECOD (1.6)

Domain Annotation: CATH CATH Database Homepage

Chain	Domain	Class	Architecture	Topology	Homology	Provenance Source (Version)
T	2.60.40.10	Mainly Beta	Sandwich	Immunoglobulin-like	Immunoglobulins	CATH (utative)
R	2.60.40.10	Mainly Beta	Sandwich	Immunoglobulin-like	Immunoglobulins	CATH (utative)
P	2.60.40.10	Mainly Beta	Sandwich	Immunoglobulin-like	Immunoglobulins	CATH (utative)
N	2.60.40.10	Mainly Beta	Sandwich	Immunoglobulin-like	Immunoglobulins	CATH (utative)
S	2.60.40.10	Mainly Beta	Sandwich	Immunoglobulin-like	Immunoglobulins	CATH (utative)
Q	2.60.40.10	Mainly Beta	Sandwich	Immunoglobulin-like	Immunoglobulins	CATH (utative)
O	2.60.40.10	Mainly Beta	Sandwich	Immunoglobulin-like	Immunoglobulins	CATH (utative)
M	2.60.40.10	Mainly Beta	Sandwich	Immunoglobulin-like	Immunoglobulins	CATH (utative)
K	2.60.40.3200	Mainly Beta	Sandwich	Immunoglobulin-like	Alphavirus E2 glycoprotein, A domain	CATH (utative)
H	2.60.40.3200	Mainly Beta	Sandwich	Immunoglobulin-like	Alphavirus E2 glycoprotein, A domain	CATH (utative)
E	2.60.40.3200	Mainly Beta	Sandwich	Immunoglobulin-like	Alphavirus E2 glycoprotein, A domain	CATH (utative)
B	2.60.40.3200	Mainly Beta	Sandwich	Immunoglobulin-like	Alphavirus E2 glycoprotein, A domain	CATH (utative)
J	2.60.40.350	Mainly Beta	Sandwich	Immunoglobulin-like		CATH (utative)
G	2.60.40.350	Mainly Beta	Sandwich	Immunoglobulin-like		CATH (utative)

SAbDab Antibody Annotation SAbDab Database Homepage

Chain	Chain Class	Chain Subclass	Chain Type	Antigen Name(s)	Provenance Source
N, P, R, T	Light Chain	IGLV3	Lambda	spike glycoprotein e2	SAbDab (2025-12-05)
M, O, Q, S	Heavy Chain	IGHV1	-	spike glycoprotein e2	SAbDab (2025-12-05)

Protein Family Annotation Pfam Database Homepage

Chains	Accession	Name	Description	Comments	Source
C, F, I, L	PF00944	Alphavirus core protein (Peptidase_S3)	Alphavirus core protein	Also known as coat protein C and capsid protein C. This makes the literature very confusing. Alphaviruses consist of a nucleoprotein core, a lipid membrane which envelopes the core, and glycoprotein spikes protruding from the lipid membrane.	Domain
B, E, H, K	PF00943	Alphavirus E2 glycoprotein (Alpha_E2_glycop)	Alphavirus E2 glycoprotein	-	Family
A, D, G, J	PF01589	Alphavirus E1 glycoprotein (Alpha_E1_glycop)	Alphavirus E1 glycoprotein	-	Family

Gene Ontology: Gene Product Annotation Gene Ontology Database Homepage

Chains	Polymer	Molecular Function	Biological Process	Cellular Component
N, P, R, T	hVEEV-63 Fab light chain	-	-	-
M, O, Q, S	hVEEV-63 Fab heavy chain	-	-	-
C, F, I, L	Capsid protein	peptidase activity catalytic activity, acting on a protein serine hydrolase activity serine-type peptidase activity hydrolase activity serine-type endopeptidase activity catalytic activity endopeptidase activity RNA binding binding nucleic acid binding structural molecule activity	viral process fusion of virus membrane with host endosome membrane membrane fusion involved in viral entry into host cell symbiont-mediated perturbation of host cellular process symbiont-mediated suppression of host gene expression biological process involved in interspecies interaction between organisms symbiont-mediated perturbation of host process symbiont-mediated perturbation of host gene expression modulation of process of another organism biological process involved in interaction with host biological process involved in symbiotic interaction symbiont-mediated suppression of host signal transduction pathway symbiont-mediated suppression of host toll-like receptor signaling pathway symbiont-mediated perturbation of host signal transduction pathway viral process fusion of virus membrane with host endosome membrane membrane fusion involved in viral entry into host cell symbiont-mediated perturbation of host cellular process symbiont-mediated suppression of host gene expression biological process involved in interspecies interaction between organisms symbiont-mediated perturbation of host process symbiont-mediated perturbation of host gene expression modulation of process of another organism biological process involved in interaction with host biological process involved in symbiotic interaction symbiont-mediated suppression of host signal transduction pathway symbiont-mediated suppression of host toll-like receptor signaling pathway symbiont-mediated perturbation of host signal transduction pathway import into cell receptor-mediated endocytosis of virus by host cell transport viral life cycle establishment of localization vesicle-mediated transport localization symbiont entry into host cell clathrin-dependent endocytosis symbiont entry into host cellular process clathrin-dependent endocytosis of virus by host cell receptor-mediated endocytosis endocytosis endocytosis involved in viral entry into host cell virion attachment to host cell adhesion of symbiont to host cell adhesion of symbiont to host proteolysis metabolic process primary metabolic process protein metabolic process macromolecule metabolic process	cellular anatomical structure membrane host cell plasma membrane host cellular component host cell part host cell membrane other organism part host intracellular part host cell cytoplasm host intracellular region virion component virion membrane viral capsid icosahedral viral capsid cellular anatomical structure membrane host cell plasma membrane host cellular component host cell part host cell membrane other organism part host intracellular part host cell cytoplasm host intracellular region virion component virion membrane viral capsid icosahedral viral capsid T=4 icosahedral viral capsid host intracellular membrane-bounded organelle host cell nucleus host intracellular organelle viral membrane viral envelope
B, E, H, K	Spike glycoprotein E2	peptidase activity catalytic activity, acting on a protein serine hydrolase activity serine-type peptidase activity hydrolase activity serine-type endopeptidase activity catalytic activity endopeptidase activity RNA binding binding nucleic acid binding structural molecule activity	viral process fusion of virus membrane with host endosome membrane membrane fusion involved in viral entry into host cell symbiont-mediated perturbation of host cellular process symbiont-mediated suppression of host gene expression biological process involved in interspecies interaction between organisms symbiont-mediated perturbation of host process symbiont-mediated perturbation of host gene expression modulation of process of another organism biological process involved in interaction with host biological process involved in symbiotic interaction symbiont-mediated suppression of host signal transduction pathway symbiont-mediated suppression of host toll-like receptor signaling pathway symbiont-mediated perturbation of host signal transduction pathway viral process fusion of virus membrane with host endosome membrane membrane fusion involved in viral entry into host cell symbiont-mediated perturbation of host cellular process symbiont-mediated suppression of host gene expression biological process involved in interspecies interaction between organisms symbiont-mediated perturbation of host process symbiont-mediated perturbation of host gene expression modulation of process of another organism biological process involved in interaction with host biological process involved in symbiotic interaction symbiont-mediated suppression of host signal transduction pathway symbiont-mediated suppression of host toll-like receptor signaling pathway symbiont-mediated perturbation of host signal transduction pathway import into cell receptor-mediated endocytosis of virus by host cell transport viral life cycle establishment of localization vesicle-mediated transport localization symbiont entry into host cell clathrin-dependent endocytosis symbiont entry into host cellular process clathrin-dependent endocytosis of virus by host cell receptor-mediated endocytosis endocytosis endocytosis involved in viral entry into host cell virion attachment to host cell adhesion of symbiont to host cell adhesion of symbiont to host proteolysis metabolic process primary metabolic process protein metabolic process macromolecule metabolic process	cellular anatomical structure membrane host cell plasma membrane host cellular component host cell part host cell membrane other organism part host intracellular part host cell cytoplasm host intracellular region virion component virion membrane viral capsid icosahedral viral capsid cellular anatomical structure membrane host cell plasma membrane host cellular component host cell part host cell membrane other organism part host intracellular part host cell cytoplasm host intracellular region virion component virion membrane viral capsid icosahedral viral capsid T=4 icosahedral viral capsid host intracellular membrane-bounded organelle host cell nucleus host intracellular organelle viral membrane viral envelope
A, D, G, J	Spike glycoprotein E1	peptidase activity catalytic activity, acting on a protein serine hydrolase activity serine-type peptidase activity hydrolase activity serine-type endopeptidase activity catalytic activity endopeptidase activity RNA binding binding nucleic acid binding structural molecule activity	viral process fusion of virus membrane with host endosome membrane membrane fusion involved in viral entry into host cell symbiont-mediated perturbation of host cellular process symbiont-mediated suppression of host gene expression biological process involved in interspecies interaction between organisms symbiont-mediated perturbation of host process symbiont-mediated perturbation of host gene expression modulation of process of another organism biological process involved in interaction with host biological process involved in symbiotic interaction symbiont-mediated suppression of host signal transduction pathway symbiont-mediated suppression of host toll-like receptor signaling pathway symbiont-mediated perturbation of host signal transduction pathway viral process fusion of virus membrane with host endosome membrane membrane fusion involved in viral entry into host cell symbiont-mediated perturbation of host cellular process symbiont-mediated suppression of host gene expression biological process involved in interspecies interaction between organisms symbiont-mediated perturbation of host process symbiont-mediated perturbation of host gene expression modulation of process of another organism biological process involved in interaction with host biological process involved in symbiotic interaction symbiont-mediated suppression of host signal transduction pathway symbiont-mediated suppression of host toll-like receptor signaling pathway symbiont-mediated perturbation of host signal transduction pathway import into cell receptor-mediated endocytosis of virus by host cell transport viral life cycle establishment of localization vesicle-mediated transport localization symbiont entry into host cell clathrin-dependent endocytosis symbiont entry into host cellular process clathrin-dependent endocytosis of virus by host cell receptor-mediated endocytosis endocytosis endocytosis involved in viral entry into host cell virion attachment to host cell adhesion of symbiont to host cell adhesion of symbiont to host proteolysis metabolic process primary metabolic process protein metabolic process macromolecule metabolic process	cellular anatomical structure membrane host cell plasma membrane host cellular component host cell part host cell membrane other organism part host intracellular part host cell cytoplasm host intracellular region virion component virion membrane viral capsid icosahedral viral capsid cellular anatomical structure membrane host cell plasma membrane host cellular component host cell part host cell membrane other organism part host intracellular part host cell cytoplasm host intracellular region virion component virion membrane viral capsid icosahedral viral capsid T=4 icosahedral viral capsid host intracellular membrane-bounded organelle host cell nucleus host intracellular organelle viral membrane viral envelope

InterPro: Protein Family Classification InterPro Database Homepage

Chains	Accession	Name	Type
C, F, I, L	IPR002533	Alphavirus E3 spike glycoprotein	Domain
C, F, I, L	IPR038055	Flaviviral glycoprotein E, dimerisation domain	Homologous Superfamily
C, F, I, L	IPR014756	Immunoglobulin E-set	Homologous Superfamily
C, F, I, L	IPR042304	Alphavirus E2 glycoprotein, domain A	Homologous Superfamily
C, F, I, L	IPR036253	Flavivirus glycoprotein, central and dimerisation domain superfamily	Homologous Superfamily
C, F, I, L	IPR009003	Peptidase S1, PA clan	Homologous Superfamily
C, F, I, L	IPR042305	Alphavirus E2 glycoprotein, domain B	Homologous Superfamily
C, F, I, L	IPR042306	Alphavirus E2 glycoprotein, domain C	Homologous Superfamily
C, F, I, L	IPR000936	Alphavirus E2 glycoprotein	Family
C, F, I, L	IPR000930	Peptidase S3, togavirin	Domain
C, F, I, L	IPR002548	Alphavirus E1 glycoprotein	Domain
C, F, I, L	IPR000336	Flavivirus/Alphavirus glycoprotein, immunoglobulin-like domain superfamily	Homologous Superfamily
C, F, I, L	IPR043504	Peptidase S1, PA clan, chymotrypsin-like fold	Homologous Superfamily
B, E, H, K	IPR002533	Alphavirus E3 spike glycoprotein	Domain
B, E, H, K	IPR038055	Flaviviral glycoprotein E, dimerisation domain	Homologous Superfamily
B, E, H, K	IPR014756	Immunoglobulin E-set	Homologous Superfamily
B, E, H, K	IPR042304	Alphavirus E2 glycoprotein, domain A	Homologous Superfamily
B, E, H, K	IPR036253	Flavivirus glycoprotein, central and dimerisation domain superfamily	Homologous Superfamily
B, E, H, K	IPR009003	Peptidase S1, PA clan	Homologous Superfamily
B, E, H, K	IPR042305	Alphavirus E2 glycoprotein, domain B	Homologous Superfamily
B, E, H, K	IPR042306	Alphavirus E2 glycoprotein, domain C	Homologous Superfamily
B, E, H, K	IPR000936	Alphavirus E2 glycoprotein	Family
B, E, H, K	IPR000930	Peptidase S3, togavirin	Domain
B, E, H, K	IPR002548	Alphavirus E1 glycoprotein	Domain
B, E, H, K	IPR000336	Flavivirus/Alphavirus glycoprotein, immunoglobulin-like domain superfamily	Homologous Superfamily
B, E, H, K	IPR043504	Peptidase S1, PA clan, chymotrypsin-like fold	Homologous Superfamily
A, D, G, J	IPR002533	Alphavirus E3 spike glycoprotein	Domain
A, D, G, J	IPR038055	Flaviviral glycoprotein E, dimerisation domain	Homologous Superfamily
A, D, G, J	IPR014756	Immunoglobulin E-set	Homologous Superfamily
A, D, G, J	IPR042304	Alphavirus E2 glycoprotein, domain A	Homologous Superfamily
A, D, G, J	IPR036253	Flavivirus glycoprotein, central and dimerisation domain superfamily	Homologous Superfamily
A, D, G, J	IPR009003	Peptidase S1, PA clan	Homologous Superfamily
A, D, G, J	IPR042305	Alphavirus E2 glycoprotein, domain B	Homologous Superfamily
A, D, G, J	IPR042306	Alphavirus E2 glycoprotein, domain C	Homologous Superfamily
A, D, G, J	IPR000936	Alphavirus E2 glycoprotein	Family
A, D, G, J	IPR000930	Peptidase S3, togavirin	Domain
A, D, G, J	IPR002548	Alphavirus E1 glycoprotein	Domain
A, D, G, J	IPR000336	Flavivirus/Alphavirus glycoprotein, immunoglobulin-like domain superfamily	Homologous Superfamily
A, D, G, J	IPR043504	Peptidase S1, PA clan, chymotrypsin-like fold	Homologous Superfamily