3QO0 | pdb_00003qo0

Monoclinic form of IgG1 Fab fragment (in complex with antigenic peptide) sharing same Fv as IgA

External Resource: Annotation

Domain Annotation: ECOD Classification
Domain Annotation: CATH
IMGT Antibody Annotation
SAbDab Antibody Annotation
Gene Ontology: Gene Product Annotation
InterPro: Protein Family Classification
Pharos: Disease Associations

Domain Annotation: ECOD Classification ECOD Database Homepage

Chains	Family Name	Domain Identifier	Architecture	Possible Homology	Homology	Topology	Family	Provenance Source (Version)
B	V-set	e3qo0B3	A: a/b three-layered sandwiches	X: Subtilisin-like	H: Subtilisin-like	T: Subtilisin-like	F: V-set	ECOD (v294.1)
A	RRM_1	e3qo0A1	A: a/b three-layered sandwiches	X: beta-Grasp	H: HTH	T: winged helix domain	F: RRM_1	ECOD (v294.1)

Domain Annotation: CATH CATH Database Homepage

Chain	Domain	Class	Architecture	Topology	Homology	Provenance Source (Version)
B	2.60.40.10	Mainly Beta	Sandwich	Immunoglobulin-like	Immunoglobulins	CATH (4.3.0)
A	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	Antibody Fab Fragment	VH-CH1	Homo sapiens (human)	IGHV3-7301, IGHV3-7302, IGHJ101, IGHG101, IGHG102, IGHG103, IGHG1*04	V-DOMAIN VH, C-DOMAIN CH1	IG	FAB-GAMMA-1_KAPPA	IMGT (202611-0)
A	Antibody Fab Fragment	L-KAPPA	Homo sapiens (human)	IGKV2-2801, IGKV2D-2801, IGKJ501, IGKC01	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	Heavy Chain	IGHV3	-	peptide from tubulin beta chain	SAbDab (2026-03-27)
A	Light Chain	IGKV2	Kappa	peptide from tubulin beta chain	SAbDab (2026-03-27)

Gene Ontology: Gene Product Annotation Gene Ontology Database Homepage

Chains	Polymer	Molecular Function	Biological Process	Cellular Component
C	Peptide from Tubulin beta chain	protein binding binding protein domain specific binding GTPase activating protein binding guanyl nucleotide binding GTP binding nucleotide binding guanyl ribonucleotide binding purine ribonucleotide binding purine ribonucleoside triphosphate binding nucleoside phosphate binding ion binding purine nucleotide binding anion binding protein binding binding protein domain specific binding GTPase activating protein binding guanyl nucleotide binding GTP binding nucleotide binding guanyl ribonucleotide binding purine ribonucleotide binding purine ribonucleoside triphosphate binding nucleoside phosphate binding ion binding purine nucleotide binding anion binding heterocyclic compound binding carbohydrate derivative binding ribonucleotide binding small molecule binding protein-containing complex binding structural constituent of cytoskeleton structural molecule activity ubiquitin protein ligase binding ubiquitin-like protein ligase binding enzyme binding MHC class I protein binding signaling receptor binding MHC protein binding cation binding metal ion binding pyrophosphatase activity GTPase activity ribonucleoside triphosphate phosphatase activity hydrolase activity, acting on acid anhydrides, in phosphorus-containing anhydrides hydrolase activity hydrolase activity, acting on acid anhydrides catalytic activity	cellular process cell cycle mitotic cell cycle cell division regulation of biological process regulation of cellular component organization regulation of cellular process biological regulation cellular component organization regulation of synapse organization cell junction organization regulation of synapse structure or activity synapse organization cellular component organization or biogenesis cellular process cell cycle mitotic cell cycle cell division regulation of biological process regulation of cellular component organization regulation of cellular process biological regulation cellular component organization regulation of synapse organization cell junction organization regulation of synapse structure or activity synapse organization cellular component organization or biogenesis regulation of biological quality organelle assembly microtubule cytoskeleton organization membraneless organelle assembly spindle assembly cellular component biogenesis organelle organization cellular component assembly microtubule-based process cytoskeleton organization chromosome segregation spindle organization cell cycle process lymphocyte mediated immunity biological process involved in interspecies interaction between organisms response to stimulus immune response response to other organism defense response defense response to symbiont response to external stimulus leukocyte mediated cytotoxicity response to biotic stimulus immune effector process immune system process defense response to other organism response to stress natural killer cell mediated cytotoxicity innate immune response leukocyte mediated immunity response to external biotic stimulus natural killer cell mediated immunity cell killing localization cellular localization transport establishment of localization in cell cytoskeleton-dependent intracellular transport intracellular transport establishment of localization developmental process epithelium development cellular developmental process tissue development epithelial cell differentiation cell differentiation anatomical structure development neuroepithelial cell differentiation odontoblast differentiation columnar/cuboidal epithelial cell differentiation	extracellular exosome membrane-bounded organelle extracellular vesicle cellular anatomical structure extracellular organelle extracellular region organelle extracellular space vesicle extracellular membrane-bounded organelle intracellular anatomical structure cytoplasm cytosol membrane microdomain extracellular exosome membrane-bounded organelle extracellular vesicle cellular anatomical structure extracellular organelle extracellular region organelle extracellular space vesicle extracellular membrane-bounded organelle intracellular anatomical structure cytoplasm cytosol membrane microdomain membrane raft membrane lytic vacuole intracellular vesicle membrane-enclosed lumen cytoplasmic vesicle lumen vacuolar lumen endomembrane system intracellular organelle lumen intracellular organelle cytoplasmic vesicle lysosome vesicle lumen azurophil granule vacuole intracellular membrane-bounded organelle secretory granule lumen azurophil granule lumen organelle lumen secretory granule primary lysosome secretory vesicle mitotic spindle cytoskeleton spindle membraneless organelle intracellular membraneless organelle microtubule cytoskeleton protein-containing complex cytoplasmic ribonucleoprotein granule supramolecular complex ribonucleoprotein granule intercellular bridge nucleus organelle envelope lumen organelle envelope nuclear envelope lumen nuclear envelope cell body polymeric cytoskeletal fiber supramolecular fiber microtubule supramolecular polymer
B	Fab fragment of IMMUNOGLOBULIN G1 HEAVY CHAIN	-	-	-
A	Fab fragment of IMMUNOGLOBULIN G1 LIGHT CHAIN	-	-	-

InterPro: Protein Family Classification InterPro Database Homepage

Chains	Accession	Name	Type
C	IPR008280	Tubulin/FtsZ, C-terminal	Homologous Superfamily
C	IPR017975	Tubulin, conserved site	Conserved Site
C	IPR023123	Tubulin, C-terminal	Homologous Superfamily
C	IPR002453	Beta tubulin	Family
C	IPR013838	Beta tubulin, autoregulation binding site	Binding Site
C	IPR018316	Tubulin/FtsZ, 2-layer sandwich domain	Domain
C	IPR003008	Tubulin/FtsZ, GTPase domain	Domain
C	IPR037103	Tubulin/FtsZ-like, C-terminal domain	Homologous Superfamily
C	IPR000217	Tubulin	Family
C	IPR036525	Tubulin/FtsZ, GTPase domain superfamily	Homologous Superfamily

Pharos: Disease Associations Pharos Homepage Annotation

Chains	Drug Target	Associated Disease
C	Pharos: P07437	complex cortical dysplasia with other brain malformations 6 non-small cell lung carcinoma ovarian cancer multiple benign circumferential skin creases on limbs 1 fallopian tube carcinoma gestational trophoblastic neoplasm Hodgkin's granuloma primitive neuroectodermal tumor Kaposi's sarcoma psoriatic arthritis actinic keratosis large cell medulloblastoma Sjogren syndrome lung cancer breast cancer complex cortical dysplasia with other brain malformations 6 non-small cell lung carcinoma ovarian cancer multiple benign circumferential skin creases on limbs 1 fallopian tube carcinoma gestational trophoblastic neoplasm Hodgkin's granuloma primitive neuroectodermal tumor Kaposi's sarcoma psoriatic arthritis actinic keratosis large cell medulloblastoma Sjogren syndrome lung cancer breast cancer malignant colon neoplasm chronic obstructive pulmonary disease cutaneous lupus erythematosus Duchenne muscular dystrophy neuroblastoma ocular hypertension Hashimoto thyroiditis pancreatic ductal adenocarcinoma Hodgkins lymphoma prostate cancer kidney Wilms tumor rhabdomyosarcoma acute lymphoblastic leukemia liposarcoma testicular cancer atypical teratoid rhabdoid tumor lung carcinoma breast carcinoma malignant glioma medulloblastoma colorectal cancer mycosis fungoides endogenous depression gastric cancer open-angle glaucoma plasma cell myeloma hypertensive disorder prostate carcinoma Langerhans cell histiocytosis age-related macular degeneration lung adenocarcinoma transitional cell carcinoma autism spectrum disorder lymphoplasmacytic lymphoma Burkitt lymphoma cervical cancer multiple benign circumferential skin creases on limbs nasopharyngeal carcinoma

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.