Annotations: 4NC1

Crystal Structure of TcdA-A2 Bound to A20.1 VHH and A26.8 VHH

External Resource: Annotation

Domain Annotation: SCOP/SCOPe Classification
Domain Annotation: ECOD Classification
Domain Annotation: CATH
IMGT Antibody Annotation
SAbDab Antibody Annotation

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

Chains	Domain Info	Class	Fold	Superfamily	Family	Domain	Species	Provenance Source (Version)
C [auth E]	d4nc1e1	All beta proteins	Immunoglobulin-like beta-sandwich	Immunoglobulin	V set domains (antibody variable domain-like)	automated matches	(Lama glama ) [TaxId: 9844 ],	SCOPe (2.08)
C [auth E]	d4nc1e2	Artifacts	Tags	Tags	Tags	C-terminal Tags	(Lama glama ) [TaxId: 9844 ],	SCOPe (2.08)
F	d4nc1f1	All beta proteins	Immunoglobulin-like beta-sandwich	Immunoglobulin	V set domains (antibody variable domain-like)	automated matches	(Lama glama ) [TaxId: 9844 ],	SCOPe (2.08)
F	d4nc1f2	Artifacts	Tags	Tags	Tags	C-terminal Tags	(Lama glama ) [TaxId: 9844 ],	SCOPe (2.08)
B [auth C]	d4nc1c_	All beta proteins	Immunoglobulin-like beta-sandwich	Immunoglobulin	V set domains (antibody variable domain-like)	automated matches	(Lama glama ) [TaxId: 9844 ],	SCOPe (2.08)
E [auth D]	d4nc1d_	All beta proteins	Immunoglobulin-like beta-sandwich	Immunoglobulin	V set domains (antibody variable domain-like)	automated matches	(Lama glama ) [TaxId: 9844 ],	SCOPe (2.08)

Domain Annotation: ECOD Classification ECOD Database Homepage

Chains	Family Name	Domain Identifier	Architecture	Possible Homology	Homology	Topology	Family	Provenance Source (Version)
C [auth E]	EF-hand_1,S_100	e4nc1E1	A: beta barrels	X: dsRBD-like	H: Peptidyl-tRNA hydrolase domain-like	T: Peptidyl-tRNA hydrolase domain-like	F: EF-hand_1,S_100	ECOD (v294.2)
F	EF-hand_1,S_100	e4nc1F1	A: beta barrels	X: dsRBD-like	H: Peptidyl-tRNA hydrolase domain-like	T: Peptidyl-tRNA hydrolase domain-like	F: EF-hand_1,S_100	ECOD (v294.2)
B [auth C]	EF-hand_1,S_100	e4nc1C1	A: beta barrels	X: dsRBD-like	H: Peptidyl-tRNA hydrolase domain-like	T: Peptidyl-tRNA hydrolase domain-like	F: EF-hand_1,S_100	ECOD (v294.2)
E [auth D]	EF-hand_1,S_100	e4nc1D1	A: beta barrels	X: dsRBD-like	H: Peptidyl-tRNA hydrolase domain-like	T: Peptidyl-tRNA hydrolase domain-like	F: EF-hand_1,S_100	ECOD (v294.2)
A	ERG4_ERG24	e4nc1A2	A: beta barrels	X: Immunoglobulin-like beta-sandwich	H: Immunoglobulin-related	T: N-terminal domain of Delta(14)-sterol reductase, MaSR1	F: ERG4_ERG24	ECOD (v294.2)
D [auth B]		e4nc1B1	A: beta barrels	X: FAD-linked reductases, C-terminal domain-like	H: FAD-linked reductases-C	T: FAD-linked reductases-C	F:	ECOD (v294.2)

Domain Annotation: CATH CATH Database Homepage

Chain	Domain	Class	Architecture	Topology	Homology	Provenance Source (Version)
C [auth E]	2.60.40.10	Mainly Beta	Sandwich	Immunoglobulin-like	Immunoglobulins	CATH (4.3.0)
F	2.60.40.10	Mainly Beta	Sandwich	Immunoglobulin-like	Immunoglobulins	CATH (4.3.0)
B [auth C]	2.60.40.10	Mainly Beta	Sandwich	Immunoglobulin-like	Immunoglobulins	CATH (4.3.0)
E [auth D]	2.60.40.10	Mainly Beta	Sandwich	Immunoglobulin-like	Immunoglobulins	CATH (4.3.0)
D [auth B]	2.10.270.10	Mainly Beta	Ribbon	left handed beta-beta-3-solenoid	Cholin Binding	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
C [auth E], F	A26.8 VHH	VH	Lama glama (llama)	IGHV3S101, IGHJ401	V-DOMAIN VH	IG	(VH)	IMGT (202618-0)
B [auth C], E [auth D]	A20.1 VHH	VH	Lama glama (llama)	IGHV3S301, IGHJ401	V-DOMAIN VH	IG	(VH)	IMGT (202618-0)

SAbDab Antibody Annotation SAbDab Database Homepage

Chain	Chain Class	Chain Subclass	Chain Type	Antigen Name(s)	Provenance Source
C [auth E], F	Heavy Chain	IGHV1	-	cell wall-binding repeat protein	SAbDab (2026-05-15)
B [auth C], E [auth D]	Heavy Chain	IGHV1	-	cell wall-binding repeat protein	SAbDab (2026-05-15)

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