3K81 | pdb_00003k81

Structure of the central interaction protein from the Trypanosoma brucei editosome in complex with single domain antibodies

External Resource: Annotation

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

Domain Annotation: ECOD Classification ECOD Database Homepage

Chains	Family Name	Domain Identifier	Architecture	Possible Homology	Homology	Topology	Family	Provenance Source (Version)
A [auth C]	LAGLIDADG_2	e3k81C1	A: a/b three-layered sandwiches	X: Immunoglobulin-like beta-sandwich	H: Immunoglobulin-related	T: Immunoglobulin/Fibronectin type III/E set domains/PapD-like	F: LAGLIDADG_2	ECOD (v294.1)
B [auth D]	Phospholip_A2_1	e3k81D1	A: a/b three-layered sandwiches	X: Lipocalins/Streptavidin	H: Zn-dependent exopeptidases	T: Zn-dependent exopeptidases	F: Phospholip_A2_1	ECOD (v294.1)
C [auth A]	C1-set	e3k81A1	A: a/b three-layered sandwiches	X: Immunoglobulin-like beta-sandwich	H: Immunoglobulin-related	T: Immunoglobulin/Fibronectin type III/E set domains/PapD-like	F: C1-set	ECOD (v294.1)
D [auth B]	Phospholip_A2_1	e3k81B1	A: a/b three-layered sandwiches	X: Lipocalins/Streptavidin	H: Zn-dependent exopeptidases	T: Zn-dependent exopeptidases	F: Phospholip_A2_1	ECOD (v294.1)

Domain Annotation: CATH CATH Database Homepage

Chain	Domain	Class	Architecture	Topology	Homology	Provenance Source (Version)
A [auth C]	2.40.50.140	Mainly Beta	Beta Barrel	OB fold (Dihydrolipoamide Acetyltransferase, E2P)	Nucleic acid-binding proteins	CATH (4.3.0)
B [auth D]	2.40.50.140	Mainly Beta	Beta Barrel	OB fold (Dihydrolipoamide Acetyltransferase, E2P)	Nucleic acid-binding proteins	CATH (4.3.0)
C [auth A]	2.60.40.10	Mainly Beta	Sandwich	Immunoglobulin-like	Immunoglobulins	CATH (4.3.0)
D [auth B]	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
C [auth A], D [auth B]	Llama heavy chain VH domain	VH	Lama glama (llama)	IGHV3S301, IGHJ401	V-DOMAIN VH	IG	(VH)	IMGT (202612-0)

SAbDab Antibody Annotation SAbDab Database Homepage

Chain	Chain Class	Chain Subclass	Chain Type	Antigen Name(s)	Provenance Source
C [auth A], D [auth B]	Heavy Chain	IGHV1	-	mp18 rna editing complex protein	SAbDab (2026-03-27)

Protein Family Annotation Pfam Database Homepage

Chains	Accession	Name	Description	Comments	Source
A [auth C], B [auth D]	PF00436	Single-strand binding protein family (SSB)	Single-strand binding protein family	This family includes single stranded binding proteins and also the primosomal replication protein N (PriB). PriB forms a complex with PriA, PriC and ssDNA.	Domain

Gene Ontology: Gene Product Annotation Gene Ontology Database Homepage

Chains	Polymer	Molecular Function	Biological Process	Cellular Component
A [auth C], B [auth D]	MP18 RNA editing complex protein	endonuclease activity nuclease activity catalytic activity, acting on a nucleic acid catalytic activity RNA binding binding nucleic acid binding DNA binding single-stranded DNA binding	nucleobase-containing compound metabolic process RNA modification macromolecule modification RNA metabolic process metabolic process cellular process primary metabolic process macromolecule metabolic process nucleic acid metabolic process	membrane-bounded organelle intracellular organelle cellular anatomical structure intracellular anatomical structure mitochondrion organelle cytoplasm intracellular membrane-bounded organelle kinetoplast mitochondrial protein-containing complex protein-containing complex catalytic complex mRNA editing complex mitochondrial mRNA editing complex membrane-bounded organelle intracellular organelle cellular anatomical structure intracellular anatomical structure mitochondrion organelle cytoplasm intracellular membrane-bounded organelle kinetoplast mitochondrial protein-containing complex protein-containing complex catalytic complex mRNA editing complex mitochondrial mRNA editing complex nucleus
C [auth A], D [auth B]	Single strand antibody VHH domain	-	-	-

InterPro: Protein Family Classification InterPro Database Homepage

Chains	Accession	Name	Type
A [auth C], B [auth D]	IPR000424	Primosome PriB/single-strand DNA-binding	Family
A [auth C], B [auth D]	IPR017084	RNA editing complex, subunit MP18	Family
A [auth C], B [auth D]	IPR012340	Nucleic acid-binding, OB-fold	Homologous Superfamily

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.