Annotations: 4KAQ

Structure of rituximab Fab

External Resource: Annotation

Domain Annotation: SCOP/SCOPe Classification
Domain Annotation: ECOD Classification
Domain Annotation: CATH
IMGT Antibody Annotation
SAbDab Antibody Annotation
Thera-SAbDab Antibody Annotation
Protein Modification Annotation

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

Chains	Domain Info	Class	Fold	Superfamily	Family	Domain	Species	Provenance Source (Version)
B [auth H]	d4kaqh_	All beta proteins	Immunoglobulin-like beta-sandwich	Immunoglobulin	automated matches	automated matches	human (Homo sapiens ) [TaxId: 9606 ], house mouse (Mus musculus ) [TaxId: 10090 ],	SCOPe (2.08)
A [auth L]	d4kaql2	All beta proteins	Immunoglobulin-like beta-sandwich	Immunoglobulin	C1 set domains (antibody constant domain-like)	automated matches	human (Homo sapiens ) [TaxId: 9606 ], house mouse (Mus musculus ) [TaxId: 10090 ],	SCOPe (2.08)
A [auth L]	d4kaql1	All beta proteins	Immunoglobulin-like beta-sandwich	Immunoglobulin	automated matches	automated matches	human (Homo sapiens ) [TaxId: 9606 ], house mouse (Mus musculus ) [TaxId: 10090 ],	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 H]		e4kaqH1	A: alpha arrays	X: CCHC-type 1 zinc finger	H: Retrovirus zinc finger-related domains	T: Retrovirus zinc finger-related domains	F:	ECOD (v295.2)
A [auth L]		e4kaqL1	A: alpha arrays	X: CCHC-type 1 zinc finger	H: Retrovirus zinc finger-related domains	T: Retrovirus zinc finger-related domains	F:	ECOD (v295.2)

Domain Annotation: CATH CATH Database Homepage

Chain	Domain	Class	Architecture	Topology	Homology	Provenance Source (Version)
B [auth H]	2.60.40.10	Mainly Beta	Sandwich	Immunoglobulin-like	Immunoglobulins	CATH (4.3.0)
A [auth L]	2.60.40.10	Mainly Beta	Sandwich	Immunoglobulin-like	Immunoglobulins	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
B [auth H]	IDEC-C2B8	VH-CH1	-	IGHV1-1201, IGHJ101, IGHJ102, IGHG101, IGHG102, IGHG104	V-DOMAIN VH, C-DOMAIN CH1	IG	FAB-GAMMA-1_KAPPA	IMGT (202637-0)
A [auth L]	IDEC-C2B8	L-KAPPA	-	IGKV4-7201, IGKJ101, IGKJ201, IGKC01	V-DOMAIN V-KAPPA, C-DOMAIN C-KAPPA	IG	FAB-GAMMA-1_KAPPA	IMGT (202637-0)

SAbDab Antibody Annotation SAbDab Database Homepage

Chain	Chain Class	Chain Subclass	Chain Type	Antigen Name(s)	Provenance Source
B [auth H]	Heavy Chain	IGHV1	-	-	SAbDab (2026-09-25)
A [auth L]	Light Chain	IGKV4	Kappa	-	SAbDab (2026-09-25)

Thera-SAbDab Antibody Annotation Thera-SAbDab Database Homepage

Chain	Name	Target	Provenance Source
B [auth H]	Rituximab	MS4A1/CD20	Therapeutic SAbDab (2026-09-25)
A [auth L]	Ripertamab	MS4A1/CD20	Therapeutic SAbDab (2026-09-25)

Protein Modification Annotation

Modified Residue(s)
Chain	Residue(s)	Description
B [auth H]	PCA	Parent Component: GLN : AA0031 : 2-pyrrolidone-5-carboxylic acid (Gln) MOD:00040 , 2-pyrrolidone-5-carboxylic acid (Glu) MOD:00420