Annotations: 4LHQ

Ricin A chain bound to camelid nanobody (VHH8)

External Resource: Annotation

Domain Annotation: SCOP/SCOPe Classification
Domain Annotation: ECOD Classification
Domain Annotation: CATH
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)
D	d4lhqd_	All beta proteins	Immunoglobulin-like beta-sandwich	Immunoglobulin	V set domains (antibody variable domain-like)	automated matches	(Vicugna pacos ) [TaxId: 30538 ],	SCOPe (2.08)
B	d4lhqb_	All beta proteins	Immunoglobulin-like beta-sandwich	Immunoglobulin	V set domains (antibody variable domain-like)	automated matches	(Vicugna pacos ) [TaxId: 30538 ],	SCOPe (2.08)
C	d4lhqc_	Alpha and beta proteins (a+b)	Ribosome inactivating proteins (RIP)	Ribosome inactivating proteins (RIP)	Plant cytotoxins	automated matches	Castor bean (Ricinus communis ) [TaxId: 3988 ],	SCOPe (2.08)
A	d4lhqa_	Alpha and beta proteins (a+b)	Ribosome inactivating proteins (RIP)	Ribosome inactivating proteins (RIP)	Plant cytotoxins	automated matches	Castor bean (Ricinus communis ) [TaxId: 3988 ],	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	Hormone_recep	e4lhqD1	A: alpha arrays	X: HTH	H: HTH	T: winged helix domain	F: Hormone_recep	ECOD (v295.2)
B	Hormone_recep	e4lhqB1	A: alpha arrays	X: HTH	H: HTH	T: winged helix domain	F: Hormone_recep	ECOD (v295.2)
C	Hormone_recep	e4lhqC1	A: alpha arrays	X: HTH	H: HTH	T: winged helix domain	F: Hormone_recep	ECOD (v295.2)
A	Hormone_recep	e4lhqA1	A: alpha arrays	X: HTH	H: HTH	T: winged helix domain	F: Hormone_recep	ECOD (v295.2)

Domain Annotation: CATH CATH Database Homepage

Chain	Domain	Class	Architecture	Topology	Homology	Provenance Source (Version)
D	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)
C	3.40.420.10	Alpha Beta	3-Layer(aba) Sandwich	Ricin (A subunit)	domain 1	CATH (4.3.0)
C	4.10.470.10	Few Secondary Structures	Irregular	Ricin (A Subunit), domain 2	Ricin (A Subunit), domain 2	CATH (4.3.0)
A	3.40.420.10	Alpha Beta	3-Layer(aba) Sandwich	Ricin (A subunit)	domain 1	CATH (4.3.0)
A	4.10.470.10	Few Secondary Structures	Irregular	Ricin (A Subunit), domain 2	Ricin (A Subunit), domain 2	CATH (4.3.0)

SAbDab Antibody Annotation SAbDab Database Homepage

Chain	Chain Class	Chain Subclass	Chain Type	Antigen Name(s)	Provenance Source
B, D	Heavy Chain	IGHV1	-	ricin	SAbDab (2026-10-16)

Gene Ontology: Gene Product Annotation Gene Ontology Database Homepage

Chains	Polymer	Molecular Function	Biological Process	Cellular Component
B, D	Camelid nanobody	-	-	-
A, C	Ricin	binding carbohydrate binding hydrolase activity, acting on glycosyl bonds rRNA N-glycosylase activity catalytic activity, acting on RNA catalytic activity, acting on a nucleic acid hydrolase activity catalytic activity, acting on a rRNA catalytic activity RNA glycosylase activity hydrolase activity, hydrolyzing N-glycosyl compounds adenyl ribonucleotide binding nucleotide binding purine ribonucleotide binding binding carbohydrate binding hydrolase activity, acting on glycosyl bonds rRNA N-glycosylase activity catalytic activity, acting on RNA catalytic activity, acting on a nucleic acid hydrolase activity catalytic activity, acting on a rRNA catalytic activity RNA glycosylase activity hydrolase activity, hydrolyzing N-glycosyl compounds adenyl ribonucleotide binding nucleotide binding purine ribonucleotide binding cation binding AMP binding nucleoside phosphate binding ion binding purine nucleotide binding anion binding adenyl nucleotide binding heterocyclic compound binding carbohydrate derivative binding ribonucleotide binding small molecule binding	regulation of cellular process negative regulation of biological process protein biosynthetic process regulation of primary metabolic process post-transcriptional regulation of gene expression negative regulation of translation negative regulation of cellular process protein metabolic process negative regulation of protein metabolic process negative regulation of macromolecule metabolic process regulation of biosynthetic process regulation of biological process regulation of protein metabolic process negative regulation of metabolic process regulation of cellular process negative regulation of biological process protein biosynthetic process regulation of primary metabolic process post-transcriptional regulation of gene expression negative regulation of translation negative regulation of cellular process protein metabolic process negative regulation of protein metabolic process negative regulation of macromolecule metabolic process regulation of biosynthetic process regulation of biological process regulation of protein metabolic process negative regulation of metabolic process biological regulation primary metabolic process regulation of macromolecule metabolic process gene expression translation macromolecule biosynthetic process regulation of gene expression negative regulation of gene expression biosynthetic process negative regulation of biosynthetic process regulation of translation negative regulation of macromolecule biosynthetic process regulation of macromolecule biosynthetic process metabolic process cellular process macromolecule metabolic process regulation of metabolic process biological process involved in interspecies interaction between organisms disruption of cell in another organism disruption of anatomical structure in another organism killing of cells of another organism cell killing	-

InterPro: Protein Family Classification InterPro Database Homepage

Chains	Accession	Name	Type
A, C	IPR016139	Ribosome-inactivating protein, subdomain 2	Homologous Superfamily
A, C	IPR016138	Ribosome-inactivating protein, subdomain 1	Homologous Superfamily
A, C	IPR001574	Ribosome-inactivating protein	Family
A, C	IPR036041	Ribosome-inactivating protein superfamily	Homologous Superfamily
A, C	IPR017988	Ribosome-inactivating protein conserved site	Conserved Site
A, C	IPR017989	Ribosome-inactivating protein type 1/2	Family
A, C	IPR035992	Ricin B-like lectins	Homologous Superfamily
A, C	IPR000772	Ricin B, lectin domain	Domain