1a8r

GTP CYCLOHYDROLASE I (H112S MUTANT) IN COMPLEX WITH GTP

Method: X-RAY DIFFRACTION

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

GTP CYCLOHYDROLASE I

Escherichia coli

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein homooligomer	Homooligomer	Protein 10	GUANOSINE-5'-TRIPHOSPHATE × 10 water × 10	Consistent with protein count
2	Protein homooligomer	Homooligomer	Protein 10	GUANOSINE-5'-TRIPHOSPHATE × 10 water × 10	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	GCH1_ECOLI
Isoform	—
PDB entities	1
Chains and sequence ranges	Author chain A； PDBConstruct 1–221； UniProt 1–221 Author chain B； PDBConstruct 1–221； UniProt 1–221 Author chain C； PDBConstruct 1–221； UniProt 1–221 Author chain D； PDBConstruct 1–221； UniProt 1–221 Author chain E； PDBConstruct 1–221； UniProt 1–221 Author chain F； PDBConstruct 1–221； UniProt 1–221 Author chain G； PDBConstruct 1–221； UniProt 1–221 Author chain H； PDBConstruct 1–221； UniProt 1–221 Author chain I； PDBConstruct 1–221； UniProt 1–221 Author chain J； PDBConstruct 1–221； UniProt 1–221 Author chain K； PDBConstruct 1–221； UniProt 1–221 Author chain L； PDBConstruct 1–221； UniProt 1–221 Author chain M； PDBConstruct 1–221； UniProt 1–221 Author chain N； PDBConstruct 1–221； UniProt 1–221 Author chain O； PDBConstruct 1–221； UniProt 1–221

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	1a8r
Deposition date deposition_date	1998-03-27
Structure title title	GTP CYCLOHYDROLASE I (H112S MUTANT) IN COMPLEX WITH GTP
Keywords keywords	HYDROLASE, GTP, PURINE HYDROLYSIS, PTERINE SYNTHESIS; 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.

1a8r__assembly_1__model_1

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

Download this curve (.dat)

1a8r__assembly_1__model_1 | I(q)

100 plotted points; both axes use logarithmic scales.

1a8r__assembly_1__model_1 | P(r) · Pending

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

Rg（Guinier）	37.79 Å
Rg (electron density)	37.04 Å
Total Rg	37.61 Å
Atom count	17600
Residues	2210
Excluded volume	312870 Å³
Maximum q	0.500 Å⁻¹

Assembly	Model	Structure unit	Oligomeric description	Status	CRYSOL	Actions
1	1	`1a8r__assembly_1__model_1`	decameric （10）	Success	4.1.3-1-20251215 (887e7ef)	View Download
2	1	`1a8r__assembly_2__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	24682.4 kDa
EC 编号 ec_number	3.5.4.16
Mutation mutation	H112S
Source method src_method	man
Copy count entity_count	15

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	A,B,C,D,E,F,G,H,I,J,K,L,M,N,O
Atom count atom_count	27375

PSLSKEAALVHEALVARGLETPLRPPVHEMDNETRKSLIAGHMTEIMQLLNLDLADDSLMETPHRIAKMYVDEIFSGLDYANFPKITLIENKMKVDEMVTVRDITLTSTCESHFVTIDGKATVAYIPKDSVIGLSKINRIVQFFAQRPQVQERLTQQILIALQTLLGTNNVAVSIDAVHYCVKARGIRDATSATTTTSLGGLFKSSQNTRHEFLRAVRHHN

Source Source

Source organism organism	Escherichia coli
NCBI taxonomy ID ncbi_taxonomy_id	562
Host organism host_organism	Escherichia coli

Entity 2 Entity 2 non-polymer

Description description	GUANOSINE-5'-TRIPHOSPHATE
Molecular weight formula_weight	523.2 kDa
Source method src_method	syn
Copy count entity_count	15

Entity 3 Entity 3 water

Description description	water
Molecular weight formula_weight	18.0 kDa
Source method src_method	nat
Copy count entity_count	975

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6. Fold Classification (SCOP + CATH) 45 domains

SCOP 2.08 (15 domains)

Domain ID domain_id	d1a8ra_
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	d1a8rb_
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	d1a8rc_
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	d1a8rd_
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	d1a8re_
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	d1a8rf_
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	d1a8rg_
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	d1a8rh_
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	d1a8ri_
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	d1a8rj_
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	d1a8rk_
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	d1a8rl_
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	d1a8rm_
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	d1a8rn_
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	d1a8ro_
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 (30 domains)

Domain ID domain_id	1a8rA01
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	1a8rA02
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	1a8rB01
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	1a8rB02
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	1a8rC01
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	1a8rC02
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	1a8rD01
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	1a8rD02
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	1a8rE01
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	1a8rE02
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	1a8rF01
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	1a8rF02
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	1a8rG01
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	1a8rG02
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	1a8rH01
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	1a8rH02
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	1a8rI01
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	1a8rI02
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	1a8rJ01
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	1a8rJ02
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	1a8rK01
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	1a8rK02
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	1a8rL01
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	1a8rL02
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	1a8rM01
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	1a8rM02
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	1a8rN01
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	1a8rN02
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	1a8rO01
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	1a8rO02
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	314.950 Å
Unit-cell length b length_b	219.140 Å
Unit-cell length c length_c	131.410 Å
Unit-cell angle α angle_alpha	90.00 °
Unit-cell angle β angle_beta	90.00 °
Unit-cell angle γ angle_gamma	90.00 °
Molecules per unit cell Z z_pdb	120

Space group space_group	C 2 2 21
Space-group number int_tables_number	20
Crystal system crystal_system	—

Resolution resolution	2.100 Å
Low-resolution limit resolution_low	8.000 Å
R factor r_factor	0.2000
R_work r_work	0.2000
R_free r_free	0.2460

GTP CYCLOHYDROLASE I (H112S MUTANT) IN COMPLEX WITH GTP

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

1a8r__assembly_1__model_1

1a8r__assembly_1__model_1 | I(q)

1a8r__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 water

6. Fold Classification (SCOP + CATH) 45 domains

SCOP 2.08 (15 domains)

CATH v4.4 (30 domains)

7. Citations (5)

GTP CYCLOHYDROLASE I (H112S MUTANT) IN COMPLEX WITH GTP

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

1a8r__assembly_1__model_1

1a8r__assembly_1__model_1 | I(q)

1a8r__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 water

6. Fold Classification (SCOP + CATH) 45 domains

SCOP 2.08 (15 domains)

CATH v4.4 (30 domains)

7. Citations (5)