1fb1

CRYSTAL STRUCTURE OF HUMAN GTP CYCLOHYDROLASE I

Method: X-RAY DIFFRACTION

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1. Protein Identity and Related Structures Protein Identity & Related Structures

GTP CYCLOHYDROLASE I

Homo sapiens

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein homooligomer	Homooligomer	Protein 10	ZINC ION × 10 ISOPROPYL ALCOHOL × 10	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	GCH1_HUMAN
Isoform	—
PDB entities	1
Chains and sequence ranges	Author chain A； PDBConstruct 1–196； UniProt 55–250 Author chain B； PDBConstruct 1–196； UniProt 55–250 Author chain C； PDBConstruct 1–196； UniProt 55–250 Author chain D； PDBConstruct 1–196； UniProt 55–250 Author chain E； PDBConstruct 1–196； UniProt 55–250

The page prioritizes protein identity, the current assembly, associated components, oligomeric state and cross-PDB links. Chain mapping and sequence ranges are retained as data evidence. Internal IDs, import timestamps and assembly operation expressions are maintenance fields and are not shown here.

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2. Structure Basics 2. Structure Basics

Entry ID entry_id	1fb1
Deposition date deposition_date	2000-07-14
Structure title title	CRYSTAL STRUCTURE OF HUMAN GTP CYCLOHYDROLASE I
Keywords keywords	HYDROLASE, ALLOSTERIC ENZYME, PHOSPHORYLATION; HYDROLASE
Experimental Method method	X-RAY DIFFRACTION

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3. Official assembly/model SAXS Official SAXS Profiles

This page reads only the latest assembly calculations. Every curve maps to an explicit PDB entry, official biological assembly and coordinate model.

1fb1__assembly_1__model_1

Assembly 1 · Model 1 · CRYSOL 4.1.3-1-20251215 (887e7ef)

Download this curve (.dat)

1fb1__assembly_1__model_1 | I(q)

100 plotted points; both axes use logarithmic scales.

1fb1__assembly_1__model_1 | P(r) · Pending

P(r) will be calculated and displayed separately for the same assembly/model.

Rg（Guinier）	37.35 Å
Rg (electron density)	36.08 Å
Total Rg	36.44 Å
Atom count	15500
Residues	1960
Excluded volume	277560 Å³
Maximum q	0.500 Å⁻¹

Assembly	Model	Structure unit	Oligomeric description	Status	CRYSOL	Actions
1	1	`1fb1__assembly_1__model_1`	decameric （10）	Success	4.1.3-1-20251215 (887e7ef)	View Download

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4. Crystallography and Experiment 4. Crystallography & Experiment

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5. Entities and Polymers Entities & Polymers (3)

Entity 1 Entity 1 polymer

Description description	GTP CYCLOHYDROLASE I
Molecular weight formula_weight	22105.5 kDa
EC 编号 ec_number	3.5.4.16
Source method src_method	man
Copy count entity_count	5

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	A,B,C,D,E
Atom count atom_count	7750

GERPRSEEDNELNLPNLAAAYSSILSSLGENPQRQGLLKTPWRAASAMQFFTKGYQETISDVLNDAIFDEDHDEMVIVKDIDMFSMCEHHLVPFVGKVHIGYLPNKQVLGLSKLARIVEIYSRRLQVQERLTKQIAVAITEALRPAGVGVVVEATHMCMVMRGVQKMNSKTVTSTMLGVFREDPKTREEFLTLIRS

Source Source

Source organism organism	Homo sapiens
Common name common_name	human
NCBI taxonomy ID ncbi_taxonomy_id	9606
Host organism host_organism	Escherichia coli

Entity 2 Entity 2 non-polymer

Description description	ZINC ION
Molecular weight formula_weight	65.4 kDa
Source method src_method	syn
Copy count entity_count	5

Entity 3 Entity 3 non-polymer

Description description	ISOPROPYL ALCOHOL
Molecular weight formula_weight	60.1 kDa
Source method src_method	syn
Copy count entity_count	5

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6. Fold Classification (SCOP + CATH) 15 domains

SCOP 2.08 (5 domains)

Domain ID domain_id	d1fb1a_
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.96 — T-fold
Superfamily Superfamily superfamily	d.96.1 — Tetrahydrobiopterin biosynthesis enzymes-like
Family Family family	d.96.1.1 — GTP cyclohydrolase I

Domain ID domain_id	d1fb1b_
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.96 — T-fold
Superfamily Superfamily superfamily	d.96.1 — Tetrahydrobiopterin biosynthesis enzymes-like
Family Family family	d.96.1.1 — GTP cyclohydrolase I

Domain ID domain_id	d1fb1c_
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.96 — T-fold
Superfamily Superfamily superfamily	d.96.1 — Tetrahydrobiopterin biosynthesis enzymes-like
Family Family family	d.96.1.1 — GTP cyclohydrolase I

Domain ID domain_id	d1fb1d_
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.96 — T-fold
Superfamily Superfamily superfamily	d.96.1 — Tetrahydrobiopterin biosynthesis enzymes-like
Family Family family	d.96.1.1 — GTP cyclohydrolase I

Domain ID domain_id	d1fb1e_
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.96 — T-fold
Superfamily Superfamily superfamily	d.96.1 — Tetrahydrobiopterin biosynthesis enzymes-like
Family Family family	d.96.1.1 — GTP cyclohydrolase I

CATH v4.4 (10 domains)

Domain ID domain_id	1fb1A01
Class class	1 — Mainly Alpha
Architecture architecture	10 — Orthogonal Bundle
Topology topology	286 — GTP Cyclohydrolase I; Chain A, domain 1
Homologous superfamily homologous superfamily	10 — GTP cyclohydrolase I, N-terminal domain

Domain ID domain_id	1fb1A02
Class class	3 — Alpha Beta
Architecture architecture	30 — 2-Layer Sandwich
Topology topology	1130 — GTP Cyclohydrolase I, domain 2
Homologous superfamily homologous superfamily	10 — GTP cyclohydrolase I, C-terminal domain/NADPH-dependent 7-cyano-7-deazaguanine reductase, N-terminal domain

Domain ID domain_id	1fb1B01
Class class	1 — Mainly Alpha
Architecture architecture	10 — Orthogonal Bundle
Topology topology	286 — GTP Cyclohydrolase I; Chain A, domain 1
Homologous superfamily homologous superfamily	10 — GTP cyclohydrolase I, N-terminal domain

Domain ID domain_id	1fb1B02
Class class	3 — Alpha Beta
Architecture architecture	30 — 2-Layer Sandwich
Topology topology	1130 — GTP Cyclohydrolase I, domain 2
Homologous superfamily homologous superfamily	10 — GTP cyclohydrolase I, C-terminal domain/NADPH-dependent 7-cyano-7-deazaguanine reductase, N-terminal domain

Domain ID domain_id	1fb1C01
Class class	1 — Mainly Alpha
Architecture architecture	10 — Orthogonal Bundle
Topology topology	286 — GTP Cyclohydrolase I; Chain A, domain 1
Homologous superfamily homologous superfamily	10 — GTP cyclohydrolase I, N-terminal domain

Domain ID domain_id	1fb1C02
Class class	3 — Alpha Beta
Architecture architecture	30 — 2-Layer Sandwich
Topology topology	1130 — GTP Cyclohydrolase I, domain 2
Homologous superfamily homologous superfamily	10 — GTP cyclohydrolase I, C-terminal domain/NADPH-dependent 7-cyano-7-deazaguanine reductase, N-terminal domain

Domain ID domain_id	1fb1D01
Class class	1 — Mainly Alpha
Architecture architecture	10 — Orthogonal Bundle
Topology topology	286 — GTP Cyclohydrolase I; Chain A, domain 1
Homologous superfamily homologous superfamily	10 — GTP cyclohydrolase I, N-terminal domain

Domain ID domain_id	1fb1D02
Class class	3 — Alpha Beta
Architecture architecture	30 — 2-Layer Sandwich
Topology topology	1130 — GTP Cyclohydrolase I, domain 2
Homologous superfamily homologous superfamily	10 — GTP cyclohydrolase I, C-terminal domain/NADPH-dependent 7-cyano-7-deazaguanine reductase, N-terminal domain

Domain ID domain_id	1fb1E01
Class class	1 — Mainly Alpha
Architecture architecture	10 — Orthogonal Bundle
Topology topology	286 — GTP Cyclohydrolase I; Chain A, domain 1
Homologous superfamily homologous superfamily	10 — GTP cyclohydrolase I, N-terminal domain

Domain ID domain_id	1fb1E02
Class class	3 — Alpha Beta
Architecture architecture	30 — 2-Layer Sandwich
Topology topology	1130 — GTP Cyclohydrolase I, domain 2
Homologous superfamily homologous superfamily	10 — GTP cyclohydrolase I, C-terminal domain/NADPH-dependent 7-cyano-7-deazaguanine reductase, N-terminal domain

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Unit-cell length a length_a	115.110 Å
Unit-cell length b length_b	115.110 Å
Unit-cell length c length_c	387.310 Å
Unit-cell angle α angle_alpha	90.00 °
Unit-cell angle β angle_beta	90.00 °
Unit-cell angle γ angle_gamma	120.00 °
Molecules per unit cell Z z_pdb	60

Space group space_group	P 65 2 2
Space-group number int_tables_number	179
Crystal system crystal_system	—

Resolution resolution	3.100 Å
Low-resolution limit resolution_low	14.970 Å
R factor r_factor	0.2040
R_work r_work	0.2040
R_free r_free	0.2930

CRYSTAL STRUCTURE OF HUMAN GTP CYCLOHYDROLASE I

1. Protein Identity and Related Structures Protein Identity & Related Structures

GTP CYCLOHYDROLASE I

State in the Current Structure

Other States of the Same Protein in the Database

2. Structure Basics 2. Structure Basics

3. Official assembly/model SAXS Official SAXS Profiles

1fb1__assembly_1__model_1

1fb1__assembly_1__model_1 | I(q)

1fb1__assembly_1__model_1 | P(r) · Pending

4. Crystallography and Experiment 4. Crystallography & Experiment

Unit cell Unit Cell

Symmetry Symmetry

Refinement Refinement

Diffraction experiment Diffraction

5. Entities and Polymers Entities & Polymers (3)

Entity 1 Entity 1 polymer

Polymer Polymer

Source Source

Entity 2 Entity 2 non-polymer

Entity 3 Entity 3 non-polymer

6. Fold Classification (SCOP + CATH) 15 domains

SCOP 2.08 (5 domains)

CATH v4.4 (10 domains)

7. Citations (1)

CRYSTAL STRUCTURE OF HUMAN GTP CYCLOHYDROLASE I

1. Protein Identity and Related Structures Protein Identity & Related Structures

GTP CYCLOHYDROLASE I

State in the Current Structure

Other States of the Same Protein in the Database

Monomer

Homodimer

Homotetramer

Other homooligomers

Heteromeric or nucleic-acid complex

2. Structure Basics 2. Structure Basics

3. Official assembly/model SAXS Official SAXS Profiles

1fb1__assembly_1__model_1

1fb1__assembly_1__model_1 | I(q)

1fb1__assembly_1__model_1 | P(r) · Pending

4. Crystallography and Experiment 4. Crystallography & Experiment

Unit cell Unit Cell

Symmetry Symmetry

Refinement Refinement

Diffraction experiment Diffraction

5. Entities and Polymers Entities & Polymers (3)

Entity 1 Entity 1 polymer

Polymer Polymer

Source Source

Entity 2 Entity 2 non-polymer

Entity 3 Entity 3 non-polymer

6. Fold Classification (SCOP + CATH) 15 domains

SCOP 2.08 (5 domains)

CATH v4.4 (10 domains)

7. Citations (1)