1QLR | pdb_00001qlr

CRYSTAL STRUCTURE OF THE FAB FRAGMENT OF A HUMAN MONOCLONAL IgM COLD AGGLUTININ

External Resource: Annotation

Domain Annotation: SCOP/SCOPe 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	d1qlra1	All beta proteins	Immunoglobulin-like beta-sandwich	Immunoglobulin	V set domains (antibody variable domain-like)	Immunoglobulin light chain kappa variable domain, VL-kappa	(Homo sapiens ) [TaxId: 9606 ],	SCOPe (2.08)
A	d1qlra2	All beta proteins	Immunoglobulin-like beta-sandwich	Immunoglobulin	C1 set domains (antibody constant domain-like)	Immunoglobulin light chain kappa constant domain, CL-kappa	(Homo sapiens ) [TaxId: 9606 ],	SCOPe (2.08)
C	d1qlrc1	All beta proteins	Immunoglobulin-like beta-sandwich	Immunoglobulin	V set domains (antibody variable domain-like)	Immunoglobulin light chain kappa variable domain, VL-kappa	(Homo sapiens ) [TaxId: 9606 ],	SCOPe (2.08)
C	d1qlrc2	All beta proteins	Immunoglobulin-like beta-sandwich	Immunoglobulin	C1 set domains (antibody constant domain-like)	Immunoglobulin light chain kappa constant domain, CL-kappa	(Homo sapiens ) [TaxId: 9606 ],	SCOPe (2.08)
B	d1qlrb1	All beta proteins	Immunoglobulin-like beta-sandwich	Immunoglobulin	V set domains (antibody variable domain-like)	Immunoglobulin heavy chain variable domain, VH	(Homo sapiens ) [TaxId: 9606 ],	SCOPe (2.08)
B	d1qlrb2	All beta proteins	Immunoglobulin-like beta-sandwich	Immunoglobulin	C1 set domains (antibody constant domain-like)	Immunoglobulin heavy chain mu constant domain 1, CH1-mu	(Homo sapiens ) [TaxId: 9606 ],	SCOPe (2.08)
D	d1qlrd1	All beta proteins	Immunoglobulin-like beta-sandwich	Immunoglobulin	V set domains (antibody variable domain-like)	Immunoglobulin heavy chain variable domain, VH	(Homo sapiens ) [TaxId: 9606 ],	SCOPe (2.08)
D	d1qlrd2	All beta proteins	Immunoglobulin-like beta-sandwich	Immunoglobulin	C1 set domains (antibody constant domain-like)	Immunoglobulin heavy chain mu constant domain 1, CH1-mu	(Homo sapiens ) [TaxId: 9606 ],	SCOPe (2.08)

Domain Annotation: ECOD Classification ECOD Database Homepage

Chains	Family Name	Domain Identifier	Architecture	Possible Homology	Homology	Topology	Family	Provenance Source (Version)
A	Copper-bind	e1qlrA1	A: alpha bundles	X: Cloacin translocation domain	H: beta-Prism I	T: beta-Prism I	F: Copper-bind	ECOD (develop294)
C	Copper-bind	e1qlrC1	A: alpha bundles	X: Cloacin translocation domain	H: beta-Prism I	T: beta-Prism I	F: Copper-bind	ECOD (develop294)
B	Copper-bind	e1qlrB1	A: alpha bundles	X: Cloacin translocation domain	H: beta-Prism I	T: beta-Prism I	F: Copper-bind	ECOD (develop294)
D	Copper-bind	e1qlrD1	A: alpha bundles	X: Cloacin translocation domain	H: beta-Prism I	T: beta-Prism I	F: Copper-bind	ECOD (develop294)

Domain Annotation: CATH CATH Database Homepage

Chain	Domain	Class	Architecture	Topology	Homology	Provenance Source (Version)
A	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)
B	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)

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, C	Kau cold agglutinin	L-KAPPA	Homo sapiens (human)	IGKV3D-2001, IGKJ401, IGKJ402, IGKC01	V-DOMAIN V-KAPPA, C-DOMAIN C-KAPPA	IG	FAB-MU_KAPPA	IMGT (202610-0)
B, D	Kau cold agglutinin	VH-CH1	Homo sapiens (human)	IGHV4-3401, IGHV4-3402, IGHJ401, IGHJ402, IGHJ403, IGHM03	V-DOMAIN VH, C-DOMAIN CH1	IG	FAB-MU_KAPPA	IMGT (202610-0)

SAbDab Antibody Annotation SAbDab Database Homepage

Chain	Chain Class	Chain Subclass	Chain Type	Antigen Name(s)	Provenance Source
A, C	Light Chain	IGKV3D	Kappa	-	SAbDab (2026-03-20)
B, D	Heavy Chain	IGHV4	-	-	SAbDab (2026-03-20)

Gene Ontology: Gene Product Annotation Gene Ontology Database Homepage

Chains	Polymer	Molecular Function	Biological Process	Cellular Component
A, C	IGM KAPPA CHAIN V-III (KAU COLD AGGLUTININ)	-	response to stimulus immune response immune system process adaptive immune response	cell periphery cellular anatomical structure plasma membrane membrane protein-containing complex immunoglobulin complex extracellular region
B, D	IGM FAB REGION IV-J(H4)-C (KAU COLD AGGLUTININ)	-	-	-

InterPro: Protein Family Classification InterPro Database Homepage

Chains	Accession	Name	Type
A, C	IPR003597	Immunoglobulin C1-set	Domain
A, C	IPR050150	Immunoglobulin Variable Light Chain	Family
A, C	IPR013783	Immunoglobulin-like fold	Homologous Superfamily
A, C	IPR036179	Immunoglobulin-like domain superfamily	Homologous Superfamily
A, C	IPR013106	Immunoglobulin V-set domain	Domain
A, C	IPR003599	Immunoglobulin domain subtype	Domain
A, C	IPR007110	Immunoglobulin-like domain	Domain
A, C	IPR003006	Immunoglobulin/major histocompatibility complex, conserved site	Conserved Site

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.