Annotations: 1FBX

Domain Annotation: SCOP/SCOPe Classification SCOP Database Homepage

Chains	Domain Info	Class	Fold	Superfamily	Family	Domain	Species	Provenance Source (Version)
A	d1fbxa_	Alpha and beta proteins (a+b)	T-fold	Tetrahydrobiopterin biosynthesis enzymes-like	GTP cyclohydrolase I	GTP cyclohydrolase I	(Escherichia coli ) [TaxId: 562 ],	SCOPe (2.08)
B	d1fbxb_	Alpha and beta proteins (a+b)	T-fold	Tetrahydrobiopterin biosynthesis enzymes-like	GTP cyclohydrolase I	GTP cyclohydrolase I	(Escherichia coli ) [TaxId: 562 ],	SCOPe (2.08)
C	d1fbxc_	Alpha and beta proteins (a+b)	T-fold	Tetrahydrobiopterin biosynthesis enzymes-like	GTP cyclohydrolase I	GTP cyclohydrolase I	(Escherichia coli ) [TaxId: 562 ],	SCOPe (2.08)
D	d1fbxd_	Alpha and beta proteins (a+b)	T-fold	Tetrahydrobiopterin biosynthesis enzymes-like	GTP cyclohydrolase I	GTP cyclohydrolase I	(Escherichia coli ) [TaxId: 562 ],	SCOPe (2.08)
E	d1fbxe_	Alpha and beta proteins (a+b)	T-fold	Tetrahydrobiopterin biosynthesis enzymes-like	GTP cyclohydrolase I	GTP cyclohydrolase I	(Escherichia coli ) [TaxId: 562 ],	SCOPe (2.08)
F	d1fbxf_	Alpha and beta proteins (a+b)	T-fold	Tetrahydrobiopterin biosynthesis enzymes-like	GTP cyclohydrolase I	GTP cyclohydrolase I	(Escherichia coli ) [TaxId: 562 ],	SCOPe (2.08)
G	d1fbxg_	Alpha and beta proteins (a+b)	T-fold	Tetrahydrobiopterin biosynthesis enzymes-like	GTP cyclohydrolase I	GTP cyclohydrolase I	(Escherichia coli ) [TaxId: 562 ],	SCOPe (2.08)
H	d1fbxh_	Alpha and beta proteins (a+b)	T-fold	Tetrahydrobiopterin biosynthesis enzymes-like	GTP cyclohydrolase I	GTP cyclohydrolase I	(Escherichia coli ) [TaxId: 562 ],	SCOPe (2.08)
I	d1fbxi_	Alpha and beta proteins (a+b)	T-fold	Tetrahydrobiopterin biosynthesis enzymes-like	GTP cyclohydrolase I	GTP cyclohydrolase I	(Escherichia coli ) [TaxId: 562 ],	SCOPe (2.08)
J	d1fbxj_	Alpha and beta proteins (a+b)	T-fold	Tetrahydrobiopterin biosynthesis enzymes-like	GTP cyclohydrolase I	GTP cyclohydrolase I	(Escherichia coli ) [TaxId: 562 ],	SCOPe (2.08)
K	d1fbxk_	Alpha and beta proteins (a+b)	T-fold	Tetrahydrobiopterin biosynthesis enzymes-like	GTP cyclohydrolase I	GTP cyclohydrolase I	(Escherichia coli ) [TaxId: 562 ],	SCOPe (2.08)
L	d1fbxl_	Alpha and beta proteins (a+b)	T-fold	Tetrahydrobiopterin biosynthesis enzymes-like	GTP cyclohydrolase I	GTP cyclohydrolase I	(Escherichia coli ) [TaxId: 562 ],	SCOPe (2.08)
M	d1fbxm_	Alpha and beta proteins (a+b)	T-fold	Tetrahydrobiopterin biosynthesis enzymes-like	GTP cyclohydrolase I	GTP cyclohydrolase I	(Escherichia coli ) [TaxId: 562 ],	SCOPe (2.08)
N	d1fbxn_	Alpha and beta proteins (a+b)	T-fold	Tetrahydrobiopterin biosynthesis enzymes-like	GTP cyclohydrolase I	GTP cyclohydrolase I	(Escherichia coli ) [TaxId: 562 ],	SCOPe (2.08)
O	d1fbxo_	Alpha and beta proteins (a+b)	T-fold	Tetrahydrobiopterin biosynthesis enzymes-like	GTP cyclohydrolase I	GTP cyclohydrolase I	(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	Tetrahydrobiopterin biosynthesis enzymes-like	8035783	3000283	SCOP2B (2022-06-29)
B	SCOP2B Superfamily	Tetrahydrobiopterin biosynthesis enzymes-like	8035783	3000283	SCOP2B (2022-06-29)
C	SCOP2B Superfamily	Tetrahydrobiopterin biosynthesis enzymes-like	8035783	3000283	SCOP2B (2022-06-29)
D	SCOP2B Superfamily	Tetrahydrobiopterin biosynthesis enzymes-like	8035783	3000283	SCOP2B (2022-06-29)
E	SCOP2B Superfamily	Tetrahydrobiopterin biosynthesis enzymes-like	8035783	3000283	SCOP2B (2022-06-29)
F	SCOP2B Superfamily	Tetrahydrobiopterin biosynthesis enzymes-like	8035783	3000283	SCOP2B (2022-06-29)
G	SCOP2B Superfamily	Tetrahydrobiopterin biosynthesis enzymes-like	8035783	3000283	SCOP2B (2022-06-29)
H	SCOP2B Superfamily	Tetrahydrobiopterin biosynthesis enzymes-like	8035783	3000283	SCOP2B (2022-06-29)
I	SCOP2B Superfamily	Tetrahydrobiopterin biosynthesis enzymes-like	8035783	3000283	SCOP2B (2022-06-29)
J	SCOP2B Superfamily	Tetrahydrobiopterin biosynthesis enzymes-like	8035783	3000283	SCOP2B (2022-06-29)
K	SCOP2B Superfamily	Tetrahydrobiopterin biosynthesis enzymes-like	8035783	3000283	SCOP2B (2022-06-29)
L	SCOP2B Superfamily	Tetrahydrobiopterin biosynthesis enzymes-like	8035783	3000283	SCOP2B (2022-06-29)
M	SCOP2B Superfamily	Tetrahydrobiopterin biosynthesis enzymes-like	8035783	3000283	SCOP2B (2022-06-29)
N	SCOP2B Superfamily	Tetrahydrobiopterin biosynthesis enzymes-like	8035783	3000283	SCOP2B (2022-06-29)
O	SCOP2B Superfamily	Tetrahydrobiopterin biosynthesis enzymes-like	8035783	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	e1fbxA1	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	e1fbxB1	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	e1fbxC1	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	e1fbxD1	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	e1fbxE1	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)
F	GTP_cyclohydroI	e1fbxF1	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)
G	GTP_cyclohydroI	e1fbxG1	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)
H	GTP_cyclohydroI	e1fbxH1	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)
I	GTP_cyclohydroI	e1fbxI1	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)
J	GTP_cyclohydroI	e1fbxJ1	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)
K	GTP_cyclohydroI	e1fbxK1	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)
L	GTP_cyclohydroI	e1fbxL1	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)
M	GTP_cyclohydroI	e1fbxM1	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)
N	GTP_cyclohydroI	e1fbxN1	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)
O	GTP_cyclohydroI	e1fbxO1	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)
F	1.10.286.10	Mainly Alpha	Orthogonal Bundle	GTP Cyclohydrolase I	Chain A, domain 1	CATH (4.3.0)
F	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)
G	1.10.286.10	Mainly Alpha	Orthogonal Bundle	GTP Cyclohydrolase I	Chain A, domain 1	CATH (4.3.0)
G	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)
H	1.10.286.10	Mainly Alpha	Orthogonal Bundle	GTP Cyclohydrolase I	Chain A, domain 1	CATH (4.3.0)
H	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)
I	1.10.286.10	Mainly Alpha	Orthogonal Bundle	GTP Cyclohydrolase I	Chain A, domain 1	CATH (4.3.0)
I	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)
J	1.10.286.10	Mainly Alpha	Orthogonal Bundle	GTP Cyclohydrolase I	Chain A, domain 1	CATH (4.3.0)
J	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)
K	1.10.286.10	Mainly Alpha	Orthogonal Bundle	GTP Cyclohydrolase I	Chain A, domain 1	CATH (4.3.0)
K	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)
L	1.10.286.10	Mainly Alpha	Orthogonal Bundle	GTP Cyclohydrolase I	Chain A, domain 1	CATH (4.3.0)
L	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)
M	1.10.286.10	Mainly Alpha	Orthogonal Bundle	GTP Cyclohydrolase I	Chain A, domain 1	CATH (4.3.0)
M	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)
N	1.10.286.10	Mainly Alpha	Orthogonal Bundle	GTP Cyclohydrolase I	Chain A, domain 1	CATH (4.3.0)
N	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)
O	1.10.286.10	Mainly Alpha	Orthogonal Bundle	GTP Cyclohydrolase I	Chain A, domain 1	CATH (4.3.0)
O	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 A, B, C, D, E, F, G, H, I, J, K, L, M, N, O	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 A, B, C, D, E, F, G, H, I, J, K, L, M, N, O	GTP CYCLOHYDROLASE I	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 cation binding transition metal ion binding zinc ion binding ion binding 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 cation binding transition metal ion binding zinc ion binding ion binding binding metal ion binding small molecule 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 binding	glycosyl compound metabolic process organonitrogen compound biosynthetic process carbohydrate derivative metabolic process nucleoside biosynthetic process queuosine metabolic process nucleobase-containing compound metabolic process queuosine biosynthetic process organic substance metabolic process nucleobase-containing small molecule metabolic process organic substance biosynthetic process small molecule metabolic process carbohydrate derivative biosynthetic process organonitrogen compound metabolic process glycosyl compound biosynthetic process glycosyl compound metabolic process organonitrogen compound biosynthetic process carbohydrate derivative metabolic process nucleoside biosynthetic process queuosine metabolic process nucleobase-containing compound metabolic process queuosine biosynthetic process organic substance metabolic process nucleobase-containing small molecule metabolic process organic substance biosynthetic process small molecule metabolic process carbohydrate derivative biosynthetic process organonitrogen compound metabolic process glycosyl compound biosynthetic process small molecule biosynthetic process primary metabolic process ribonucleoside biosynthetic process nucleobase-containing compound biosynthetic process nucleoside metabolic process nucleobase-containing small molecule biosynthetic process organic cyclic compound metabolic process biosynthetic process organic cyclic compound biosynthetic process metabolic process ribonucleoside metabolic process cellular metabolic process cellular process one-carbon metabolic process polyol metabolic process organic hydroxy compound metabolic process alcohol metabolic process diol biosynthetic process diol metabolic process tetrahydrobiopterin biosynthetic process tetrahydrobiopterin metabolic process organic hydroxy compound biosynthetic process pteridine-containing compound biosynthetic process polyol biosynthetic process alcohol biosynthetic process pteridine-containing compound metabolic process 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	intracellular anatomical structure cytoplasm cellular anatomical entity cytosol protein-containing complex

InterPro: Protein Family Classification InterPro Database Homepage

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

Structure Motif Annotation: Mechanism and Catalytic Site Atlas M-CSA Database Homepage

Chains	Enzyme Name	Description	Catalytic Residues
A	GTP cyclohydrolase I M-CSA #38	GTP cyclohydrolase I catalyses the complex reaction which converts GTP to dihydroneopterin triphosphate. This is the first step of a pathway, which in plants and micro-organisms leads to tetrahydrofolate production, and in animals leads to tetrahydrobiopterin production. Tetrahydrobiopterin is biologically important as it serves as a cofactor in the production of catecholamines and nitric oxide. Genetic defects in GTP cyclohydrolase can therefore lead to severe neurological disorders. Enzymes involved in the formation of tetrahydrofolate are also important anti-infection drug targets. Allosteric enzyme. Activity is modulated by K+, divalent cations, UTP, and tetrahydrobiopterin. Tetrahydrobiopterin is an inhibitor of this enzyme.	Defined by 7 residues: CYS:A-110GLU:A-111HIS:A-112HIS:A-113GLN:A-151HIS:A-179CYS:A-181 \| Explore in 3D: M-CSA Motif Definition Search M-CSA Motif EC: 3.5.4.16 (PDB Primary Data) Search M-CSA Motif + EC 3.5.4.16