Annotations: 8S4U

Domain Annotation: ECOD Classification ECOD Database Homepage

Chains	Family Name	Domain Identifier	Architecture	Possible Homology	Homology	Topology	Family	Provenance Source (Version)
A [auth B]	Gln-synt_C	e8s4uB01	A: a/b three-layered sandwiches	X: ATP-grasp_6	H: ATP-grasp_6	T: ATP-grasp_6	F: Gln-synt_C	ECOD (v294.1)
B [auth A]	Gln-synt_C	e8s4uA01	A: a/b three-layered sandwiches	X: ATP-grasp_6	H: ATP-grasp_6	T: ATP-grasp_6	F: Gln-synt_C	ECOD (v294.1)

SAbDab Antibody Annotation SAbDab Database Homepage

Chain	Chain Class	Chain Subclass	Chain Type	Antigen Name(s)	Provenance Source
A [auth B]	Heavy Chain	IGHV1	-	thiamine transporter 2	SAbDab (2026-04-17)

Gene Ontology: Gene Product Annotation Gene Ontology Database Homepage

Chains	Polymer	Molecular Function	Biological Process	Cellular Component
A [auth B]	Nanobody 3.4	-	-	-
B [auth A]	Thiamine transporter 2	thiamine transmembrane transporter activity azole transmembrane transporter activity sulfur compound transmembrane transporter activity vitamin transmembrane transporter activity transporter activity transmembrane transporter activity	localization nitrogen compound transport transport vitamin transport pyridoxine transport vitamin B6 transport organic hydroxy compound transport establishment of localization sulfur compound transport thiamine transport organic cation transport pyrimidine-containing compound metabolic process water-soluble vitamin biosynthetic process small molecule biosynthetic process localization nitrogen compound transport transport vitamin transport pyridoxine transport vitamin B6 transport organic hydroxy compound transport establishment of localization sulfur compound transport thiamine transport organic cation transport pyrimidine-containing compound metabolic process water-soluble vitamin biosynthetic process small molecule biosynthetic process thiamine-containing compound metabolic process vitamin biosynthetic process vitamin metabolic process sulfur compound biosynthetic process biosynthetic process organophosphate metabolic process organophosphate biosynthetic process phosphate-containing compound metabolic process thiamine diphosphate metabolic process sulfur compound metabolic process metabolic process cellular process small molecule metabolic process pyrimidine-containing compound biosynthetic process phosphorus metabolic process thiamine diphosphate biosynthetic process thiamine-containing compound biosynthetic process transmembrane transport azole transmembrane transport pyrimidine-containing compound transmembrane transport thiamine transmembrane transport vitamin transmembrane transport	cell periphery cellular anatomical structure plasma membrane membrane

InterPro: Protein Family Classification InterPro Database Homepage

Chains	Accession	Name	Type
B [auth A]	IPR002666	Reduced folate carrier	Family
B [auth A]	IPR036259	MFS transporter superfamily	Homologous Superfamily
B [auth A]	IPR028337	Thiamine transporter 2	Family

Pharos: Disease Associations Pharos Homepage Annotation

Chains	Drug Target	Associated Disease
B [auth A]	Pharos: Q9BZV2	biotin-responsive basal ganglia disease basal ganglia disease ulcerative colitis breast fibroadenoma Extrapyramidal Disorders invasive ductal breast carcinoma lung adenocarcinoma malignant colon neoplasm ovarian cancer Crohn disease inflammatory bowel disease Leigh syndrome lung cancer primary biliary cholangitis breast carcinoma biotin-responsive basal ganglia disease basal ganglia disease ulcerative colitis breast fibroadenoma Extrapyramidal Disorders invasive ductal breast carcinoma lung adenocarcinoma malignant colon neoplasm ovarian cancer Crohn disease inflammatory bowel disease Leigh syndrome lung cancer primary biliary cholangitis breast carcinoma ductal breast carcinoma in situ intellectual disability lung carcinoma non-small cell lung carcinoma

Membrane Protein Annotation: PDBTM PDBTM Database Homepage

Chains	External Link	Comment
B [auth A]	PDBTM	Annotated as membrane protein by PDBTM

Membrane Protein Annotation: MemProtMD MemProtMD Database Homepage

Chains	External Link	Comment
B [auth A]	MemProtMD	Annotated as membrane protein by MemProtMD

Membrane Protein Annotation: mpstruc mpstruc Database Homepage

Chains	Resource Link	Group	Subgroup	Protein
B [auth A]	mpstruc	TRANSMEMBRANE PROTEINS: ALPHA-HELICAL	Solute Carrier (SLC) Transporter Superfamily	SLC19A3 thiamine transporter 2, apo form, outward-open state

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.