4ZS6 | pdb_00004zs6

Receptor binding domain and Fab complex

External Resource: Annotation

Domain Annotation: SCOP/SCOPe Classification
Domain Annotation: SCOP2 Classification
Domain Annotation: ECOD Classification
Domain Annotation: CATH
IMGT Antibody Annotation
SAbDab Antibody Annotation
Gene Ontology: Gene Product Annotation
InterPro: Protein Family Classification

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

Chains	Domain Info	Class	Fold	Superfamily	Family	Domain	Species	Provenance Source (Version)
A [auth L]	d4zs6l2	All beta proteins	Immunoglobulin-like beta-sandwich	Immunoglobulin	C1 set domains (antibody constant domain-like)	automated matches	(Homo sapiens ) [TaxId: 9606 ],	SCOPe (2.08)
A [auth L]	d4zs6l1	All beta proteins	Immunoglobulin-like beta-sandwich	Immunoglobulin	automated matches	automated matches	(Homo sapiens ) [TaxId: 9606 ],	SCOPe (2.08)
D	d4zs6d2	All beta proteins	Immunoglobulin-like beta-sandwich	Immunoglobulin	C1 set domains (antibody constant domain-like)	automated matches	(Homo sapiens ) [TaxId: 9606 ],	SCOPe (2.08)
D	d4zs6d1	All beta proteins	Immunoglobulin-like beta-sandwich	Immunoglobulin	automated matches	automated matches	(Homo sapiens ) [TaxId: 9606 ],	SCOPe (2.08)
B [auth H]	d4zs6h_	All beta proteins	Immunoglobulin-like beta-sandwich	Immunoglobulin	V set domains (antibody variable domain-like)	automated matches	(Homo sapiens ) [TaxId: 9606 ],	SCOPe (2.08)
E [auth C]	d4zs6c_	All beta proteins	Immunoglobulin-like beta-sandwich	Immunoglobulin	V set domains (antibody variable domain-like)	automated matches	(Homo sapiens ) [TaxId: 9606 ],	SCOPe (2.08)

Domain Annotation: SCOP2 Classification SCOP2 Database Homepage

Chains	Type	Family Name	Domain Identifier	Family Identifier	Provenance Source (Version)
C [auth A]	SCOP2 Family	SARS coronavirus receptor-binding domain-like	8082391	4003874	SCOP2 (2022-06-29)
C [auth A]	SCOP2 Superfamily	SARS coronavirus receptor-binding domain-like	8082392	3001706	SCOP2 (2022-06-29)
F [auth B]	SCOP2B Superfamily	SARS coronavirus receptor-binding domain-like	8082392	3001706	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 [auth L]	CPV_Polyhedrin	e4zs6L1	A: alpha bundles	X: ssDNA-binding transcriptional regulator domain-like	H: ssDNA-binding transcriptional regulator domain	T: ssDNA-binding transcriptional regulator domain	F: CPV_Polyhedrin	ECOD (develop294)
D	CPV_Polyhedrin	e4zs6D1	A: alpha bundles	X: ssDNA-binding transcriptional regulator domain-like	H: ssDNA-binding transcriptional regulator domain	T: ssDNA-binding transcriptional regulator domain	F: CPV_Polyhedrin	ECOD (develop294)
B [auth H]	CPV_Polyhedrin	e4zs6H1	A: alpha bundles	X: ssDNA-binding transcriptional regulator domain-like	H: ssDNA-binding transcriptional regulator domain	T: ssDNA-binding transcriptional regulator domain	F: CPV_Polyhedrin	ECOD (develop294)
B [auth H]	EF-hand_1, EF-hand_6, EF-hand_7	e4zs6H2	A: alpha bundles	X: Lipocalins/Streptavidin	H: SAM/DNA-glycosylase	T: SAM domain-like	F: EF-hand_1, EF-hand_6, EF-hand_7	ECOD (develop294)
E [auth C]	CPV_Polyhedrin	e4zs6C2	A: alpha bundles	X: ssDNA-binding transcriptional regulator domain-like	H: ssDNA-binding transcriptional regulator domain	T: ssDNA-binding transcriptional regulator domain	F: CPV_Polyhedrin	ECOD (develop294)
E [auth C]	EF-hand_1, EF-hand_6, EF-hand_7	e4zs6C3	A: alpha bundles	X: Lipocalins/Streptavidin	H: SAM/DNA-glycosylase	T: SAM domain-like	F: EF-hand_1, EF-hand_6, EF-hand_7	ECOD (develop294)
C [auth A]	CPV_Polyhedrin	e4zs6A1	A: alpha bundles	X: ssDNA-binding transcriptional regulator domain-like	H: ssDNA-binding transcriptional regulator domain	T: ssDNA-binding transcriptional regulator domain	F: CPV_Polyhedrin	ECOD (develop294)
F [auth B]	CPV_Polyhedrin	e4zs6B1	A: alpha bundles	X: ssDNA-binding transcriptional regulator domain-like	H: ssDNA-binding transcriptional regulator domain	T: ssDNA-binding transcriptional regulator domain	F: CPV_Polyhedrin	ECOD (develop294)

Domain Annotation: CATH CATH Database Homepage

Chain	Domain	Class	Architecture	Topology	Homology	Provenance Source (Version)
A [auth L]	2.60.40.10	Mainly Beta	Sandwich	Immunoglobulin-like	Immunoglobulins	CATH (4.3.0)
D	2.60.40.10	Mainly Beta	Sandwich	Immunoglobulin-like	Immunoglobulins	CATH (4.3.0)
B [auth H]	2.60.40.10	Mainly Beta	Sandwich	Immunoglobulin-like	Immunoglobulins	CATH (4.3.0)
E [auth C]	2.60.40.10	Mainly Beta	Sandwich	Immunoglobulin-like	Immunoglobulins	CATH (4.3.0)
C [auth A]	3.30.70.1840	Alpha Beta	2-Layer Sandwich	Alpha-Beta Plaits	Spike protein, C-terminal core receptor binding subdomain	CATH (4.3.0)
C [auth A]	2.20.210.30	Mainly Beta	Single Sheet	ubp-family deubiquitinating enzyme fold		CATH (4.3.0)
F [auth B]	3.30.70.1840	Alpha Beta	2-Layer Sandwich	Alpha-Beta Plaits	Spike protein, C-terminal core receptor binding subdomain	CATH (4.3.0)
F [auth B]	2.20.210.30	Mainly Beta	Single Sheet	ubp-family deubiquitinating enzyme fold		CATH (4.3.0)

IMGT Antibody Annotation IMGT Database Homepage

Chain	Protein Name	Description	Organism Name	Gene Allele Name(s)	Domain Name(s)	Receptor Type	Receptor Description	Provenance Source
A [auth L], D	Fab MERS-27	L-KAPPA	Homo sapiens (human)	IGKV1-3301, IGKV1D-3301, IGKJ501, IGKC01	V-DOMAIN V-KAPPA, C-DOMAIN C-KAPPA	IG	FAB-GAMMA-1_KAPPA	IMGT (202610-0)
B [auth H], E [auth C]	Fab MERS-27	VH-CH1	Homo sapiens (human)	IGHV3-1103, IGHJ101, IGHG101, IGHG102, IGHG104, IGHG105	V-DOMAIN VH, C-DOMAIN CH1	IG	FAB-GAMMA-1_KAPPA	IMGT (202610-0)

SAbDab Antibody Annotation SAbDab Database Homepage

Chain	Chain Class	Chain Subclass	Chain Type	Antigen Name(s)	Provenance Source
A [auth L], D	Light Chain	IGKV1	Kappa	s protein	SAbDab (2026-03-20)
B [auth H], E [auth C]	Heavy Chain	IGHV3	-	s protein	SAbDab (2026-03-20)

Gene Ontology: Gene Product Annotation Gene Ontology Database Homepage

Chains	Polymer	Molecular Function	Biological Process	Cellular Component
A [auth L], D	fab Light Chain	-	-	-
B [auth H], E [auth C]	fab Heavy Chain	-	-	-
C [auth A], F [auth B]	S protein	-	viral process fusion of virus membrane with host endosome membrane membrane fusion involved in viral entry into host cell virion attachment to host cell biological process involved in interspecies interaction between organisms receptor-mediated virion attachment to host cell adhesion of symbiont to host cell viral life cycle adhesion of symbiont to host biological process involved in interaction with host biological process involved in symbiotic interaction membrane organization cellular component organization membrane fusion viral process fusion of virus membrane with host endosome membrane membrane fusion involved in viral entry into host cell virion attachment to host cell biological process involved in interspecies interaction between organisms receptor-mediated virion attachment to host cell adhesion of symbiont to host cell viral life cycle adhesion of symbiont to host biological process involved in interaction with host biological process involved in symbiotic interaction membrane organization cellular component organization membrane fusion fusion of virus membrane with host plasma membrane cellular process cellular component organization or biogenesis symbiont entry into host cell symbiont entry into host endocytosis involved in viral entry into host cell	cellular anatomical structure membrane virion component virion membrane host intracellular membrane-bounded organelle host cellular component host intracellular part host cell membrane other organism part host cell cytoplasm part host intracellular organelle host cell endoplasmic reticulum-Golgi intermediate compartment membrane host cell endoplasmic reticulum-Golgi intermediate compartment host cell cytoplasm cellular anatomical structure membrane virion component virion membrane host intracellular membrane-bounded organelle host cellular component host intracellular part host cell membrane other organism part host cell cytoplasm part host intracellular organelle host cell endoplasmic reticulum-Golgi intermediate compartment membrane host cell endoplasmic reticulum-Golgi intermediate compartment host cell cytoplasm host cell part host intracellular region viral membrane viral envelope host cell plasma membrane

InterPro: Protein Family Classification InterPro Database Homepage

Chains	Accession	Name	Type
C [auth A], F [auth B]	IPR018548	Spike (S) protein S1 subunit, receptor-binding domain, betacoronavirus	Domain
C [auth A], F [auth B]	IPR032500	Spike glycoprotein S1, N-terminal domain, betacoronavirus-like	Domain
C [auth A], F [auth B]	IPR044376	Spike (S) protein S1 subunit, receptor-binding domain, MERS-CoV	Domain
C [auth A], F [auth B]	IPR042578	Spike glycoprotein, betacoronavirus	Family
C [auth A], F [auth B]	IPR036326	Spike S1 subunit, receptor binding domain superfamily, betacoronavirus	Homologous Superfamily
C [auth A], F [auth B]	IPR043002	Spike glycoprotein, N-terminal domain superfamily	Homologous Superfamily
C [auth A], F [auth B]	IPR044874	Spike glycoprotein S2, coronavirus, heptad repeat 2	Domain
C [auth A], F [auth B]	IPR044337	Spike (S) protein S1 subunit, N-terminal domain, MERS-CoV-like	Domain
C [auth A], F [auth B]	IPR043614	Spike glycoprotein S2, coronavirus, C-terminal	Domain
C [auth A], F [auth B]	IPR044873	Spike glycoprotein S2, coronavirus, heptad repeat 1	Domain
C [auth A], F [auth B]	IPR043473	Spike glycoprotein S2 superfamily, coronavirus	Homologous Superfamily
C [auth A], F [auth B]	IPR002552	Spike glycoprotein S2, coronavirus	Domain

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. RCSB PDB uses resources of the National Energy Research Scientific Computing Center (NERSC), a Department of Energy User Facility.