1NQH

OUTER MEMBRANE COBALAMIN TRANSPORTER (BTUB) FROM E. COLI, WITH BOUND CALCIUM AND CYANOCOBALAMIN (VITAMIN B12) SUBSTRATE

External Resource: Annotation

Domain Annotation: SCOP/SCOPe Classification
Domain Annotation: SCOP2 Classification
Domain Annotation: ECOD Classification
Domain Annotation: CATH
Protein Family Annotation
Gene Ontology: Gene Product Annotation
InterPro: Protein Family Classification
Membrane Protein Annotation: PDBTM
Membrane Protein Annotation: MemProtMD
Membrane Protein Annotation: mpstruc

Domain Annotation: SCOP/SCOPe Classification SCOP-e Database Homepage

Chains	Domain Info	Class	Fold	Superfamily	Family	Domain	Species	Provenance Source (Version)
A	d1nqha_	Membrane and cell surface proteins and peptides	Transmembrane beta-barrels	Porins	Ligand-gated protein channel	Outer membrane cobalamin transporter BtuB	(Escherichia coli ) [TaxId: 562 ],	SCOPe (2.08)

Domain Annotation: SCOP2 Classification SCOP2 Database Homepage

Chains	Type	Family Name	Domain Identifier	Family Identifier	Provenance Source (Version)
A	SCOP2B Superfamily	Porins	8042029	3000224	SCOP2B (2022-06-29)

Domain Annotation: ECOD Classification ECOD Database Homepage

Chains	Family Name	Domain Identifier	Architecture	Possible Homology	Homology	Topology	Family	Provenance Source (Version)
A	TonB_dep_Rec	e1nqhA1	A: beta barrels	X: Outer membrane meander beta-barrels	H: Porins	T: Ligand-gated protein channel	F: TonB_dep_Rec	ECOD (1.6)
A	Plug	e1nqhA2	A: a+b complex topology	X: N0 domain in phage tail proteins and secretins-like	H: TonB-dependent receptor plug domain (From Topology)	T: TonB-dependent receptor plug domain	F: Plug	ECOD (1.6)

Domain Annotation: CATH CATH Database Homepage

Chain	Domain	Class	Architecture	Topology	Homology	Provenance Source (Version)
A	2.170.130.10	Mainly Beta	Beta Complex	Ferric Hydroxamate Uptake Protein	Chain A, domain 1	CATH (4.3.0)
A	2.40.170.20	Mainly Beta	Beta Barrel	Maltoporin	Chain A	CATH (4.3.0)

Protein Family Annotation Pfam Database Homepage

Chains	Accession	Name	Description	Comments	Source
A	PF00593	TonB dependent receptor-like, beta-barrel (TonB_dep_Rec_b-barrel)	TonB dependent receptor-like, beta-barrel	This entry represents the beta-barrel domain of TonB-dependent receptors, such as BtuB, CirA, FatA, FcuT, FecA, FepA, among others [1].	Domain
A	PF07715	TonB-dependent Receptor Plug Domain (Plug)	TonB-dependent Receptor Plug Domain	The Plug domain has been shown to be an independently folding subunit of the TonB-dependent receptors ([1]). It acts as the channel gate, blocking the pore until the channel is bound by ligand. At this point it under goes conformational changes opens ...	The Plug domain has been shown to be an independently folding subunit of the TonB-dependent receptors ([1]). It acts as the channel gate, blocking the pore until the channel is bound by ligand. At this point it under goes conformational changes opens the channel.	Domain

Gene Ontology: Gene Product Annotation Gene Ontology Database Homepage

Chains	Polymer	Molecular Function	Biological Process	Cellular Component
A	VITAMIN B12 RECEPTOR	cation binding ion binding binding calcium ion binding metal ion binding small molecule binding wide pore channel activity passive transmembrane transporter activity channel activity porin activity transporter activity transmembrane transporter activity protein binding protein domain specific binding cation binding ion binding binding calcium ion binding metal ion binding small molecule binding wide pore channel activity passive transmembrane transporter activity channel activity porin activity transporter activity transmembrane transporter activity protein binding protein domain specific binding ABC-type vitamin B12 transporter activity ABC-type transporter activity active transmembrane transporter activity vitamin transmembrane transporter activity primary active transmembrane transporter activity ATPase-coupled transmembrane transporter activity ATP-dependent activity	localization nitrogen compound transport transport vitamin transport cobalamin transport establishment of localization transmembrane transport monoatomic ion transmembrane transport monoatomic ion transport cellular process	membrane cellular anatomical entity protein-containing complex transmembrane transporter complex membrane protein complex transporter complex pore complex cell periphery cell outer membrane external encapsulating structure cell envelope outer membrane

InterPro: Protein Family Classification InterPro Database Homepage

Chains	Accession	Name	Type
A	IPR039426	TonB-dependent receptor-like	Family
A	IPR037066	TonB-dependent receptor, plug domain superfamily	Homologous Superfamily
A	IPR010917	TonB-dependent receptor, conserved site	Conserved Site
A	IPR036942	TonB-dependent receptor-like, beta-barrel domain superfamily	Homologous Superfamily
A	IPR012910	TonB-dependent receptor, plug domain	Domain
A	IPR010916	TonB box, conserved site	Conserved Site
A	IPR010101	TonB-dependent vitamin B12 transporter BtuB	Family
A	IPR000531	TonB-dependent receptor-like, beta-barrel	Domain

Membrane Protein Annotation: PDBTM PDBTM Database Homepage

Chains	External Link	Comment
A	PDBTM	Annotated as membrane protein by PDBTM

Membrane Protein Annotation: MemProtMD MemProtMD Database Homepage

Chains	External Link	Comment
A	MemProtMD	Annotated as membrane protein by MemProtMD

Membrane Protein Annotation: mpstruc mpstruc Database Homepage

Chains	Resource Link	Group	Subgroup	Protein
A	mpstruc	TRANSMEMBRANE PROTEINS: BETA-BARREL	Beta-Barrel Membrane Proteins: Monomeric/Dimeric	apo BtuB cobalamin transporter

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.