1cli

X-RAY CRYSTAL STRUCTURE OF AMINOIMIDAZOLE RIBONUCLEOTIDE SYNTHETASE (PURM), FROM THE E. COLI PURINE BIOSYNTHETIC PATHWAY, AT 2.5 A RESOLUTION

Method: X-RAY DIFFRACTION

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

PROTEIN (PHOSPHORIBOSYL-AMINOIMIDAZOLE SYNTHETASE)

Escherichia coli

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein homooligomer	Homooligomer	Protein 2	SULFATE ION × 2 water × 2	Consistent with protein count
2	Protein homooligomer	Homooligomer	Protein 2	SULFATE ION × 2 water × 2	Consistent with protein count
3	Protein homooligomer	Homooligomer	Protein 2	SULFATE ION × 2 water × 2	Consistent with protein count
4	Protein homooligomer	Homooligomer	Protein 4	SULFATE ION × 4 water × 4	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	PUR5_ECOLI
Isoform	—
PDB entities	1
Chains and sequence ranges	Author chain A； PDBConstruct 2–345； UniProt 2–345 Author chain B； PDBConstruct 2–345； UniProt 2–345 Author chain C； PDBConstruct 2–345； UniProt 2–345 Author chain D； PDBConstruct 2–345； UniProt 2–345

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	1cli
Deposition date deposition_date	1999-04-28
Structure title title	X-RAY CRYSTAL STRUCTURE OF AMINOIMIDAZOLE RIBONUCLEOTIDE SYNTHETASE (PURM), FROM THE E. COLI PURINE BIOSYNTHETIC PATHWAY, AT 2.5 A RESOLUTION
Keywords keywords	AIR SYNTHETASE, PURM, PURINE BIOSYNTHESIS, TRIFUNCTIONAL ENZYME, PURL, FGAR AMIDOTRANSFERASE, NOVEL FOLD, LIGASE; LIGASE
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.

1cli__assembly_3__model_1

Assembly 3 · Model 1 · CRYSOL 4.1.3-1-20251215 (887e7ef)

Download this curve (.dat)

1cli__assembly_3__model_1 | I(q)

100 plotted points; both axes use logarithmic scales.

1cli__assembly_3__model_1 | P(r) · Pending

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

Rg（Guinier）	27.15 Å
Rg (electron density)	26.25 Å
Total Rg	26.96 Å
Atom count	5005
Residues	666
Excluded volume	89204 Å³
Maximum q	0.500 Å⁻¹

Assembly	Model	Structure unit	Oligomeric description	Status	CRYSOL	Actions
1	1	`1cli__assembly_1__model_1`	dimeric （2）	Success	4.1.3-1-20251215 (887e7ef)	View Download
2	1	`1cli__assembly_2__model_1`	dimeric （2）	Success	4.1.3-1-20251215 (887e7ef)	View Download
3	1	`1cli__assembly_3__model_1`	dimeric （2）	Success	4.1.3-1-20251215 (887e7ef)	View Download
4	1	`1cli__assembly_4__model_1`	tetrameric （4）	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	PROTEIN (PHOSPHORIBOSYL-AMINOIMIDAZOLE SYNTHETASE)
Molecular weight formula_weight	36858.9 kDa
EC 编号 ec_number	6.3.3.1
Source method src_method	man
Copy count entity_count	4

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	A,B,C,D
Atom count atom_count	10513

VTDKTSLSYKDAGVDIDAGNALVGRIKGVVKKTRRPEVMGGLGGFGALCALPQKYREPVLVSGTDGVGTKLRLAMDLKRHDTIGIDLVAMCVNDLVVQGAEPLFFLDYYATGKLDVDTASAVISGIAEGCLQSGCSLVGGETAEMPGMYHGEDYDVAGFCVGVVEKSEIIDGSKVSDGDVLIALGSSGPHSNGYSLVRKILEVSGCDPQTTELDGKPLADHLLAPTRIYVKSVLELIEKVDVHAIAHLTGGGFWENIPRVLPDNTQAVIDESSWQWPEVFNWLQTAGNVEHHEMYRTFNCGVGMIIALPAPEVDKALALLNANGENAWKIGIIKASDSEQRVVIE

Source Source

Source organism organism	Escherichia coli
NCBI taxonomy ID ncbi_taxonomy_id	562
Host organism host_organism	Escherichia coli BL21

Entity 2 Entity 2 non-polymer

Description description	SULFATE ION
Molecular weight formula_weight	96.1 kDa
Source method src_method	syn
Copy count entity_count	4

Entity 3 Entity 3 water

Description description	water
Molecular weight formula_weight	18.0 kDa
Source method src_method	nat
Copy count entity_count	503

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6. Fold Classification (SCOP + CATH) 16 domains

SCOP 2.08 (8 domains)

Domain ID domain_id	d1clia1
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.79 — Bacillus chorismate mutase-like
Superfamily Superfamily superfamily	d.79.4 — PurM N-terminal domain-like
Family Family family	d.79.4.1 — PurM N-terminal domain-like

Domain ID domain_id	d1clia2
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.139 — PurM C-terminal domain-like
Superfamily Superfamily superfamily	d.139.1 — PurM C-terminal domain-like
Family Family family	d.139.1.1 — PurM C-terminal domain-like

Domain ID domain_id	d1clib1
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.79 — Bacillus chorismate mutase-like
Superfamily Superfamily superfamily	d.79.4 — PurM N-terminal domain-like
Family Family family	d.79.4.1 — PurM N-terminal domain-like

Domain ID domain_id	d1clib2
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.139 — PurM C-terminal domain-like
Superfamily Superfamily superfamily	d.139.1 — PurM C-terminal domain-like
Family Family family	d.139.1.1 — PurM C-terminal domain-like

Domain ID domain_id	d1clic1
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.79 — Bacillus chorismate mutase-like
Superfamily Superfamily superfamily	d.79.4 — PurM N-terminal domain-like
Family Family family	d.79.4.1 — PurM N-terminal domain-like

Domain ID domain_id	d1clic2
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.139 — PurM C-terminal domain-like
Superfamily Superfamily superfamily	d.139.1 — PurM C-terminal domain-like
Family Family family	d.139.1.1 — PurM C-terminal domain-like

Domain ID domain_id	d1clid1
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.79 — Bacillus chorismate mutase-like
Superfamily Superfamily superfamily	d.79.4 — PurM N-terminal domain-like
Family Family family	d.79.4.1 — PurM N-terminal domain-like

Domain ID domain_id	d1clid2
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.139 — PurM C-terminal domain-like
Superfamily Superfamily superfamily	d.139.1 — PurM C-terminal domain-like
Family Family family	d.139.1.1 — PurM C-terminal domain-like

CATH v4.4 (8 domains)

Domain ID domain_id	1cliA01
Class class	3 — Alpha Beta
Architecture architecture	30 — 2-Layer Sandwich
Topology topology	1330 — 60s Ribosomal Protein L30; Chain: A;
Homologous superfamily homologous superfamily	10 — PurM-like, N-terminal domain

Domain ID domain_id	1cliA02
Class class	3 — Alpha Beta
Architecture architecture	90 — Alpha-Beta Complex
Topology topology	650 — Phosphoribosyl-aminoimidazole Synthetase; Chain A, domain 2
Homologous superfamily homologous superfamily	10 — PurM-like C-terminal domain

Domain ID domain_id	1cliB01
Class class	3 — Alpha Beta
Architecture architecture	30 — 2-Layer Sandwich
Topology topology	1330 — 60s Ribosomal Protein L30; Chain: A;
Homologous superfamily homologous superfamily	10 — PurM-like, N-terminal domain

Domain ID domain_id	1cliB02
Class class	3 — Alpha Beta
Architecture architecture	90 — Alpha-Beta Complex
Topology topology	650 — Phosphoribosyl-aminoimidazole Synthetase; Chain A, domain 2
Homologous superfamily homologous superfamily	10 — PurM-like C-terminal domain

Domain ID domain_id	1cliC01
Class class	3 — Alpha Beta
Architecture architecture	30 — 2-Layer Sandwich
Topology topology	1330 — 60s Ribosomal Protein L30; Chain: A;
Homologous superfamily homologous superfamily	10 — PurM-like, N-terminal domain

Domain ID domain_id	1cliC02
Class class	3 — Alpha Beta
Architecture architecture	90 — Alpha-Beta Complex
Topology topology	650 — Phosphoribosyl-aminoimidazole Synthetase; Chain A, domain 2
Homologous superfamily homologous superfamily	10 — PurM-like C-terminal domain

Domain ID domain_id	1cliD01
Class class	3 — Alpha Beta
Architecture architecture	30 — 2-Layer Sandwich
Topology topology	1330 — 60s Ribosomal Protein L30; Chain: A;
Homologous superfamily homologous superfamily	10 — PurM-like, N-terminal domain

Domain ID domain_id	1cliD02
Class class	3 — Alpha Beta
Architecture architecture	90 — Alpha-Beta Complex
Topology topology	650 — Phosphoribosyl-aminoimidazole Synthetase; Chain A, domain 2
Homologous superfamily homologous superfamily	10 — PurM-like C-terminal domain

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Unit-cell length a length_a	71.170 Å
Unit-cell length b length_b	211.680 Å
Unit-cell length c length_c	94.450 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	16

Space group space_group	P 21 21 21
Space-group number int_tables_number	19
Crystal system crystal_system	—

Resolution resolution	2.500 Å
Low-resolution limit resolution_low	20.000 Å
R factor r_factor	—
R_work r_work	0.1920
R_free r_free	0.2640

X-RAY CRYSTAL STRUCTURE OF AMINOIMIDAZOLE RIBONUCLEOTIDE SYNTHETASE (PURM), FROM THE E. COLI PURINE BIOSYNTHETIC PATHWAY, AT 2.5 A RESOLUTION

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

PROTEIN (PHOSPHORIBOSYL-AMINOIMIDAZOLE SYNTHETASE)

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

1cli__assembly_3__model_1

1cli__assembly_3__model_1 | I(q)

1cli__assembly_3__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) 16 domains

SCOP 2.08 (8 domains)

CATH v4.4 (8 domains)

7. Citations (1)

X-RAY CRYSTAL STRUCTURE OF AMINOIMIDAZOLE RIBONUCLEOTIDE SYNTHETASE (PURM), FROM THE E. COLI PURINE BIOSYNTHETIC PATHWAY, AT 2.5 A RESOLUTION

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

PROTEIN (PHOSPHORIBOSYL-AMINOIMIDAZOLE SYNTHETASE)

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

1cli__assembly_3__model_1

1cli__assembly_3__model_1 | I(q)

1cli__assembly_3__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) 16 domains

SCOP 2.08 (8 domains)

CATH v4.4 (8 domains)

7. Citations (1)