Annotations: 1FB1

Domain Annotation: SCOP/SCOPe Classification SCOP Database Homepage

Chains	Domain Info	Class	Fold	Superfamily	Family	Domain	Species	Provenance Source (Version)
A	d1fb1a_	Alpha and beta proteins (a+b)	T-fold	Tetrahydrobiopterin biosynthesis enzymes-like	GTP cyclohydrolase I	GTP cyclohydrolase I	human (Homo sapiens ) [TaxId: 9606 ],	SCOPe (2.08)
B	d1fb1b_	Alpha and beta proteins (a+b)	T-fold	Tetrahydrobiopterin biosynthesis enzymes-like	GTP cyclohydrolase I	GTP cyclohydrolase I	human (Homo sapiens ) [TaxId: 9606 ],	SCOPe (2.08)
C	d1fb1c_	Alpha and beta proteins (a+b)	T-fold	Tetrahydrobiopterin biosynthesis enzymes-like	GTP cyclohydrolase I	GTP cyclohydrolase I	human (Homo sapiens ) [TaxId: 9606 ],	SCOPe (2.08)
D	d1fb1d_	Alpha and beta proteins (a+b)	T-fold	Tetrahydrobiopterin biosynthesis enzymes-like	GTP cyclohydrolase I	GTP cyclohydrolase I	human (Homo sapiens ) [TaxId: 9606 ],	SCOPe (2.08)
E	d1fb1e_	Alpha and beta proteins (a+b)	T-fold	Tetrahydrobiopterin biosynthesis enzymes-like	GTP cyclohydrolase I	GTP cyclohydrolase I	human (Homo sapiens ) [TaxId: 9606 ],	SCOPe (2.08)

Domain Annotation: SCOP2 Classification SCOP2 Database Homepage

Chains	Type	Family Name	Domain Identifier	Family Identifier	Provenance Source (Version)
A	SCOP2 Family	GTP cyclohydrolase I	8023457	4001710	SCOP2 (2022-06-29)
A	SCOP2 Superfamily	Tetrahydrobiopterin biosynthesis enzymes-like	8035837	3000283	SCOP2 (2022-06-29)
B	SCOP2B Superfamily	Tetrahydrobiopterin biosynthesis enzymes-like	8035837	3000283	SCOP2B (2022-06-29)
C	SCOP2B Superfamily	Tetrahydrobiopterin biosynthesis enzymes-like	8035837	3000283	SCOP2B (2022-06-29)
D	SCOP2B Superfamily	Tetrahydrobiopterin biosynthesis enzymes-like	8035837	3000283	SCOP2B (2022-06-29)
E	SCOP2B Superfamily	Tetrahydrobiopterin biosynthesis enzymes-like	8035837	3000283	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	GTP_cyclohydroI	e1fb1A1	A: a+b two layers	X: T-fold	H: Tetrahydrobiopterin biosynthesis enzymes-like (From Topology)	T: Tetrahydrobiopterin biosynthesis enzymes-like	F: GTP_cyclohydroI	ECOD (1.6)
B	GTP_cyclohydroI	e1fb1B1	A: a+b two layers	X: T-fold	H: Tetrahydrobiopterin biosynthesis enzymes-like (From Topology)	T: Tetrahydrobiopterin biosynthesis enzymes-like	F: GTP_cyclohydroI	ECOD (1.6)
C	GTP_cyclohydroI	e1fb1C1	A: a+b two layers	X: T-fold	H: Tetrahydrobiopterin biosynthesis enzymes-like (From Topology)	T: Tetrahydrobiopterin biosynthesis enzymes-like	F: GTP_cyclohydroI	ECOD (1.6)
D	GTP_cyclohydroI	e1fb1D1	A: a+b two layers	X: T-fold	H: Tetrahydrobiopterin biosynthesis enzymes-like (From Topology)	T: Tetrahydrobiopterin biosynthesis enzymes-like	F: GTP_cyclohydroI	ECOD (1.6)
E	GTP_cyclohydroI	e1fb1E1	A: a+b two layers	X: T-fold	H: Tetrahydrobiopterin biosynthesis enzymes-like (From Topology)	T: Tetrahydrobiopterin biosynthesis enzymes-like	F: GTP_cyclohydroI	ECOD (1.6)

Domain Annotation: CATH CATH Database Homepage

Chain	Domain	Class	Architecture	Topology	Homology	Provenance Source (Version)
A	1.10.286.10	Mainly Alpha	Orthogonal Bundle	GTP Cyclohydrolase I	Chain A, domain 1	CATH (4.3.0)
A	3.30.1130.10	Alpha Beta	2-Layer Sandwich	GTP Cyclohydrolase I, domain 2	GTP cyclohydrolase I, C-terminal domain/NADPH-dependent 7-cyano-7-deazaguanine reductase, N-terminal domain	CATH (4.3.0)
B	1.10.286.10	Mainly Alpha	Orthogonal Bundle	GTP Cyclohydrolase I	Chain A, domain 1	CATH (4.3.0)
B	3.30.1130.10	Alpha Beta	2-Layer Sandwich	GTP Cyclohydrolase I, domain 2	GTP cyclohydrolase I, C-terminal domain/NADPH-dependent 7-cyano-7-deazaguanine reductase, N-terminal domain	CATH (4.3.0)
C	1.10.286.10	Mainly Alpha	Orthogonal Bundle	GTP Cyclohydrolase I	Chain A, domain 1	CATH (4.3.0)
C	3.30.1130.10	Alpha Beta	2-Layer Sandwich	GTP Cyclohydrolase I, domain 2	GTP cyclohydrolase I, C-terminal domain/NADPH-dependent 7-cyano-7-deazaguanine reductase, N-terminal domain	CATH (4.3.0)
D	1.10.286.10	Mainly Alpha	Orthogonal Bundle	GTP Cyclohydrolase I	Chain A, domain 1	CATH (4.3.0)
D	3.30.1130.10	Alpha Beta	2-Layer Sandwich	GTP Cyclohydrolase I, domain 2	GTP cyclohydrolase I, C-terminal domain/NADPH-dependent 7-cyano-7-deazaguanine reductase, N-terminal domain	CATH (4.3.0)
E	1.10.286.10	Mainly Alpha	Orthogonal Bundle	GTP Cyclohydrolase I	Chain A, domain 1	CATH (4.3.0)
E	3.30.1130.10	Alpha Beta	2-Layer Sandwich	GTP Cyclohydrolase I, domain 2	GTP cyclohydrolase I, C-terminal domain/NADPH-dependent 7-cyano-7-deazaguanine reductase, N-terminal domain	CATH (4.3.0)

Protein Family Annotation Pfam Database Homepage

Chains	Accession	Name	Description	Comments	Source
A, B, C, D, E	PF01227	GTP cyclohydrolase I (GTP_cyclohydroI)	GTP cyclohydrolase I	This family includes GTP cyclohydrolase enzymes and a family of related bacterial proteins including Swiss:Q46920.	Domain

Gene Ontology: Gene Product Annotation Gene Ontology Database Homepage

Chains	Polymer	Molecular Function	Biological Process	Cellular Component
A, B, C, D, E	GTP CYCLOHYDROLASE I	cation binding ion binding binding calcium ion binding metal ion binding small molecule binding hydrolase activity, acting on carbon-nitrogen (but not peptide) bonds, in cyclic amidines GTP cyclohydrolase activity cyclohydrolase activity hydrolase activity GTP cyclohydrolase I activity catalytic activity hydrolase activity, acting on carbon-nitrogen (but not peptide) bonds GTP-dependent protein binding cation binding ion binding binding calcium ion binding metal ion binding small molecule binding hydrolase activity, acting on carbon-nitrogen (but not peptide) bonds, in cyclic amidines GTP cyclohydrolase activity cyclohydrolase activity hydrolase activity GTP cyclohydrolase I activity catalytic activity hydrolase activity, acting on carbon-nitrogen (but not peptide) bonds GTP-dependent protein binding protein binding guanyl nucleotide binding GTP binding nucleotide binding guanyl ribonucleotide binding purine ribonucleotide binding purine ribonucleoside triphosphate binding nucleoside phosphate binding organic cyclic compound binding purine nucleotide binding anion binding heterocyclic compound binding carbohydrate derivative binding ribonucleotide binding identical protein binding protein homodimerization activity protein dimerization activity protein-containing complex binding kinase binding enzyme binding protein kinase binding mitogen-activated protein kinase binding transition metal ion binding zinc ion binding pyrophosphatase activity GTPase activity ribonucleoside triphosphate phosphatase activity hydrolase activity, acting on acid anhydrides, in phosphorus-containing anhydrides hydrolase activity, acting on acid anhydrides	heart process multicellular organismal process system process regulation of biological process regulation of heart contraction regulation of system process biological regulation positive regulation of biological process positive regulation of heart rate positive regulation of blood circulation positive regulation of heart contraction circulatory system process regulation of blood circulation positive regulation of multicellular organismal process heart process multicellular organismal process system process regulation of biological process regulation of heart contraction regulation of system process biological regulation positive regulation of biological process positive regulation of heart rate positive regulation of blood circulation positive regulation of heart contraction circulatory system process regulation of blood circulation positive regulation of multicellular organismal process regulation of multicellular organismal process regulation of biological quality heart contraction blood circulation regulation of heart rate response to stimulus response to stress multicellular organismal response to stress response to pain cellular component organization cellular component biogenesis cellular component assembly protein-containing complex organization protein-containing complex assembly cellular process cellular component organization or biogenesis regulation of blood pressure regulation of catalytic activity positive regulation of catalytic activity regulation of oxidoreductase activity positive regulation of oxidoreductase activity positive regulation of nitric-oxide synthase activity regulation of molecular function positive regulation of molecular function regulation of monooxygenase activity positive regulation of monooxygenase activity regulation of nitric-oxide synthase activity cellular response to stimulus regulation of cellular process cellular response to oxidative stress detoxification regulation of cellular response to stress reactive oxygen species metabolic process cellular response to chemical stress regulation of cellular response to oxidative stress response to superoxide cellular oxidant detoxification response to inorganic substance cellular response to oxygen radical cellular response to reactive oxygen species cellular response to stress regulation of response to stress regulation of response to oxidative stress cellular detoxification cellular metabolic process response to oxygen-containing compound regulation of superoxide metabolic process regulation of cellular metabolic process cellular response to oxygen-containing compound response to reactive oxygen species regulation of removal of superoxide radicals response to toxic substance superoxide metabolic process removal of superoxide radicals response to oxidative stress cellular response to chemical stimulus regulation of response to stimulus regulation of response to reactive oxygen species response to chemical cellular response to superoxide metabolic process regulation of metabolic process regulation of reactive oxygen species metabolic process cellular response to toxic substance response to oxygen radical neuron apoptotic process positive regulation of programmed cell death regulation of apoptotic process regulation of programmed cell death cell death positive regulation of apoptotic process apoptotic process positive regulation of neuron apoptotic process programmed cell death positive regulation of cellular process regulation of neuron apoptotic process cellular biosynthetic process organic hydroxy compound metabolic process organonitrogen compound biosynthetic process alcohol metabolic process diol biosynthetic process cellular nitrogen compound biosynthetic process organic substance metabolic process diol metabolic process heterocycle metabolic process organic substance biosynthetic process polyol biosynthetic process nitrogen compound metabolic process small molecule metabolic process polyol metabolic process organonitrogen compound metabolic process small molecule biosynthetic process cellular nitrogen compound metabolic process heterocycle biosynthetic process organic cyclic compound metabolic process biosynthetic process tetrahydrobiopterin biosynthetic process aromatic compound biosynthetic process organic cyclic compound biosynthetic process tetrahydrobiopterin metabolic process organic hydroxy compound biosynthetic process pteridine-containing compound biosynthetic process alcohol biosynthetic process pteridine-containing compound metabolic process cellular aromatic compound metabolic process dopamine metabolic process catechol-containing compound metabolic process biogenic amine biosynthetic process catecholamine metabolic process dopamine biosynthetic process catecholamine biosynthetic process catechol-containing compound biosynthetic process amine metabolic process amine biosynthetic process phenol-containing compound metabolic process phenol-containing compound biosynthetic process biogenic amine metabolic process regulation of tube diameter regulation of tube size vascular process in circulatory system blood vessel diameter maintenance vasodilation regulation of anatomical structure size response to organic substance biological process involved in interspecies interaction between organisms immune response response to other organism defense response response to type II interferon response to cytokine defense response to symbiont response to external stimulus response to biotic stimulus immune system process defense response to other organism innate immune response response to external biotic stimulus positive regulation of organelle organization telomere organization regulation of DNA biosynthetic process positive regulation of macromolecule biosynthetic process RNA-templated DNA biosynthetic process regulation of primary metabolic process nucleobase-containing compound metabolic process telomere maintenance via telomere lengthening regulation of nitrogen compound metabolic process positive regulation of metabolic process positive regulation of telomere maintenance via telomere lengthening positive regulation of macromolecule metabolic process regulation of nucleobase-containing compound metabolic process positive regulation of telomere maintenance positive regulation of nucleobase-containing compound metabolic process primary metabolic process DNA metabolic process regulation of chromosome organization regulation of telomere maintenance via telomere lengthening regulation of organelle organization positive regulation of chromosome organization telomere maintenance positive regulation of DNA metabolic process positive regulation of telomere maintenance via telomerase regulation of macromolecule biosynthetic process macromolecule metabolic process DNA biosynthetic process regulation of DNA metabolic process regulation of telomere maintenance regulation of cellular component organization positive regulation of cellular component organization positive regulation of cellular metabolic process nucleic acid biosynthetic process positive regulation of biosynthetic process regulation of biosynthetic process telomere maintenance via telomerase chromosome organization positive regulation of DNA biosynthetic process regulation of macromolecule metabolic process nucleobase-containing compound biosynthetic process macromolecule biosynthetic process nucleic acid metabolic process regulation of telomere maintenance via telomerase regulation of cellular biosynthetic process organelle organization positive regulation of nitrogen compound metabolic process positive regulation of cellular biosynthetic process regulation of cellular senescence negative regulation of metabolic process negative regulation of biological process cellular senescence negative regulation of cellular metabolic process negative regulation of cellular senescence negative regulation of cellular process negative regulation of cardiac muscle cell apoptotic process muscle cell apoptotic process negative regulation of programmed cell death regulation of cardiac muscle cell apoptotic process regulation of muscle cell apoptotic process cardiac muscle cell apoptotic process negative regulation of apoptotic process regulation of striated muscle cell apoptotic process striated muscle cell apoptotic process negative regulation of muscle cell apoptotic process negative regulation of striated muscle cell apoptotic process nervous system process neuromuscular process neuromuscular process controlling posture regulation of lung blood pressure folic acid-containing compound biosynthetic process cellular modified amino acid metabolic process cellular modified amino acid biosynthetic process folic acid-containing compound metabolic process tetrahydrofolate biosynthetic process tetrahydrofolate metabolic process response to lipid response to lipopolysaccharide response to bacterium response to molecule of bacterial origin negative regulation of blood pressure reactive nitrogen species metabolic process nitric oxide metabolic process nitric oxide biosynthetic process response to tumor necrosis factor	membrane-bounded organelle intracellular organelle intracellular anatomical structure mitochondrion organelle cytoplasm cellular anatomical entity intracellular membrane-bounded organelle nuclear membrane membrane nucleus endomembrane system organelle envelope nuclear envelope membrane-bounded organelle intracellular organelle intracellular anatomical structure mitochondrion organelle cytoplasm cellular anatomical entity intracellular membrane-bounded organelle nuclear membrane membrane nucleus endomembrane system organelle envelope nuclear envelope organelle membrane cytosol membrane-enclosed lumen intracellular organelle lumen nucleoplasm organelle lumen nuclear lumen protein-containing complex cytoplasmic vesicle intracellular vesicle vesicle cell projection neuron projection terminus neuron projection plasma membrane bounded cell projection

InterPro: Protein Family Classification InterPro Database Homepage

Chains	Accession	Name	Type
A, B, C, D, E	IPR018234	GTP cyclohydrolase I, conserved site	Conserved Site
A, B, C, D, E	IPR020602	GTP cyclohydrolase I domain	Domain
A, B, C, D, E	IPR043133	GTP cyclohydrolase I, C-terminal/NADPH-dependent 7-cyano-7-deazaguanine reductase	Homologous Superfamily
A, B, C, D, E	IPR043134	GTP cyclohydrolase I, N-terminal domain	Homologous Superfamily
A, B, C, D, E	IPR001474	GTP cyclohydrolase I	Family

Pharos: Disease Associations Pharos Homepage Annotation

Chains	Drug Target	Associated Disease
A, B, C, D, E	Pharos: P30793	dystonic disorder GTP cyclohydrolase I deficiency with hyperphenylalaninemia Hypokinesia Parkinson disease dopa-responsive dystonia dystonia 5 phenylketonuria hypertensive disorder bipolar disorder pancreatic ductal adenocarcinoma primitive neuroectodermal tumor Sjogren syndrome intellectual disability transitional cell carcinoma large cell medulloblastoma dystonic disorder GTP cyclohydrolase I deficiency with hyperphenylalaninemia Hypokinesia Parkinson disease dopa-responsive dystonia dystonia 5 phenylketonuria hypertensive disorder bipolar disorder pancreatic ductal adenocarcinoma primitive neuroectodermal tumor Sjogren syndrome intellectual disability transitional cell carcinoma large cell medulloblastoma major depressive disorder dermatomyositis ductal breast carcinoma in situ myocardial ischemia oligodendroglioma psoriasis sarcoidosis adenoma invasive ductal breast carcinoma breast carcinoma lung cancer coronary artery disease malignant mesothelioma osteosarcoma glioblastoma schizophrenia inborn errors of metabolism TH-deficient dopa-responsive dystonia juvenile dermatomyositis lung carcinoma cutaneous lupus erythematosus medulloblastoma drug-induced dyskinesia ovarian cancer

RCSB PDB Core Operations are funded by the National Science Foundation (DBI-1832184), 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 R01GM133198.