4M93 | pdb_00004m93

Unliganded 2 crystal structure of S25-26 Fab

External Resource: Annotation

Domain Annotation: SCOP/SCOPe Classification
Domain Annotation: ECOD Classification
Domain Annotation: CATH
IMGT Antibody Annotation
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)
D [auth B]	d4m93b_	All beta proteins	Immunoglobulin-like beta-sandwich	Immunoglobulin	V set domains (antibody variable domain-like)	automated matches	(Mus musculus ) [TaxId: 10090 ],	SCOPe (2.08)
B [auth H]	d4m93h_	All beta proteins	Immunoglobulin-like beta-sandwich	Immunoglobulin	V set domains (antibody variable domain-like)	automated matches	(Mus musculus ) [TaxId: 10090 ],	SCOPe (2.08)
C	d4m93c1	All beta proteins	Immunoglobulin-like beta-sandwich	Immunoglobulin	V set domains (antibody variable domain-like)	automated matches	(Mus musculus ) [TaxId: 10090 ],	SCOPe (2.08)
C	d4m93c2	All beta proteins	Immunoglobulin-like beta-sandwich	Immunoglobulin	C1 set domains (antibody constant domain-like)	automated matches	(Mus musculus ) [TaxId: 10090 ],	SCOPe (2.08)
A [auth L]	d4m93l1	All beta proteins	Immunoglobulin-like beta-sandwich	Immunoglobulin	V set domains (antibody variable domain-like)	automated matches	(Mus musculus ) [TaxId: 10090 ],	SCOPe (2.08)
A [auth L]	d4m93l2	All beta proteins	Immunoglobulin-like beta-sandwich	Immunoglobulin	C1 set domains (antibody constant domain-like)	automated matches	(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)
D [auth B]	Cys_knot	e4m93B1	A: a/b three-layered sandwiches	X: DEATH domain	H: HTH	T: winged helix domain	F: Cys_knot	ECOD (v294.1)
B [auth H]	Cys_knot	e4m93H1	A: a/b three-layered sandwiches	X: DEATH domain	H: HTH	T: winged helix domain	F: Cys_knot	ECOD (v294.1)
C	Cys_knot	e4m93C1	A: a/b three-layered sandwiches	X: DEATH domain	H: HTH	T: winged helix domain	F: Cys_knot	ECOD (v294.1)
A [auth L]	Cys_knot	e4m93L1	A: a/b three-layered sandwiches	X: DEATH domain	H: HTH	T: winged helix domain	F: Cys_knot	ECOD (v294.1)

Domain Annotation: CATH CATH Database Homepage

Chain	Domain	Class	Architecture	Topology	Homology	Provenance Source (Version)
D [auth B]	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)
C	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], D [auth B]	S25-26 Fab (IgG1K)	VH-CH1	Mus musculus (house mouse)	IGHV2-202, IGHJ301, IGHG1*02	V-DOMAIN VH, C-DOMAIN CH1	IG	FAB-GAMMA-1_KAPPA	IMGT (202611-0)
A [auth L], C	S25-26 Fab (IgG1K)	L-KAPPA	Mus musculus (house mouse)	IGKV1-11701, IGKJ201, IGKC01, IGKC02	V-DOMAIN V-KAPPA, C-DOMAIN C-KAPPA	IG	FAB-GAMMA-1_KAPPA	IMGT (202611-0)

SAbDab Antibody Annotation SAbDab Database Homepage

Chain	Chain Class	Chain Subclass	Chain Type	Antigen Name(s)	Provenance Source
B [auth H], D [auth B]	Heavy Chain	IGHV2	-	-	SAbDab (2026-03-27)
A [auth L], C	Light Chain	IGKV1	Kappa	-	SAbDab (2026-03-27)

Protein Modification Annotation

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

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.