SAXSdb — 1p18

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

hypoxanthine phosphoribosyltransferase

Trypanosoma cruzi

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein homooligomer	Homooligomer	Protein 2	MAGNESIUM ION × 4 7-HYDROXY-PYRAZOLO[4,3-D]PYRIMIDINE × 2 1-O-pyrophosphono-5-O-phosphono-alpha-D-ribofuranose × 2 water × 2	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	Q27796_TRYCR
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

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	1p18
Deposition date deposition_date	2003-04-11
Structure title title	Hypoxanthine Phosphoribosyltransferase from Trypanosoma cruzi, K68R mutant, ternary substrates complex
Keywords keywords	TRANSFERASE, GLYCOSYLTRANSFERASE, PHOSPHORIBOSYLTRANSFERASE, NUCLEOTIDE METABOLISM, PURINE SALVAGE, TERNARY COMPLEX; TRANSFERASE
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.

1p18__assembly_1__model_1

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

Download this curve (.dat)

1p18__assembly_1__model_1 | I(q)

100 plotted points; both axes use logarithmic scales.

1p18__assembly_1__model_1 | P(r) · Pending

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

Rg（Guinier）	21.18 Å
Rg (electron density)	20.06 Å
Total Rg	20.82 Å
Atom count	3093
Residues	381
Excluded volume	55080 Å³
Maximum q	0.500 Å⁻¹

Assembly	Model	Structure unit	Oligomeric description	Status	CRYSOL	Actions
1	1	`1p18__assembly_1__model_1`	dimeric （2）	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 (5)

Entity 1 Entity 1 polymer

Description description	hypoxanthine phosphoribosyltransferase
Molecular weight formula_weight	25623.4 kDa
EC 编号 ec_number	2.4.2.8
Mutation mutation	K52R
Source method src_method	man
Copy count entity_count	2

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	A,B
Atom count atom_count	3202

MPREYEFAEKILFTEEEIRTRIKEVAKRIADDYKGKGLRPYVNPLVLISVLRGSFMFTADLCRALCDFNVPVRMEFICVSSYGEGLTSSGQVRMLLDTRHSIEGHHVLIVEDIVDTALTLNYLYHMYFTRRPASLKTVVLLDKREGRRVPFSADYVVANIPNAFVIGYGLDYDDTYRELRDIVVLRPEVYAEREAARQKKQRAIGSADTDRDAKREFHSKY

Source Source

Source organism organism	Trypanosoma cruzi
NCBI taxonomy ID ncbi_taxonomy_id	5693
Host organism host_organism	Escherichia coli

Entity 2 Entity 2 non-polymer

Description description	MAGNESIUM ION
Molecular weight formula_weight	24.3 kDa
Source method src_method	syn
Copy count entity_count	4

Entity 3 Entity 3 non-polymer

Description description	7-HYDROXY-PYRAZOLO[4,3-D]PYRIMIDINE
Molecular weight formula_weight	136.1 kDa
Source method src_method	syn
Copy count entity_count	2

Entity 4 Entity 4 non-polymer

Description description	1-O-pyrophosphono-5-O-phosphono-alpha-D-ribofuranose
Molecular weight formula_weight	390.1 kDa
Source method src_method	syn
Copy count entity_count	2

Entity 5 Entity 5 water

Description description	water
Molecular weight formula_weight	18.0 kDa
Source method src_method	nat
Copy count entity_count	109

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6. Fold Classification (SCOP + CATH) 4 domains

SCOP 2.08 (2 domains)

Domain ID domain_id	d1p18a_
Class class	c — Alpha and beta proteins (a/b)
Fold Fold fold	c.61 — PRTase-like
Superfamily Superfamily superfamily	c.61.1 — PRTase-like
Family Family family	c.61.1.1 — Phosphoribosyltransferases (PRTases)

Domain ID domain_id	d1p18b_
Class class	c — Alpha and beta proteins (a/b)
Fold Fold fold	c.61 — PRTase-like
Superfamily Superfamily superfamily	c.61.1 — PRTase-like
Family Family family	c.61.1.1 — Phosphoribosyltransferases (PRTases)

CATH v4.4 (2 domains)

Domain ID domain_id	1p18A00
Class class	3 — Alpha Beta
Architecture architecture	40 — 3-Layer(aba) Sandwich
Topology topology	50 — Rossmann fold
Homologous superfamily homologous superfamily	2020 —

Domain ID domain_id	1p18B00
Class class	3 — Alpha Beta
Architecture architecture	40 — 3-Layer(aba) Sandwich
Topology topology	50 — Rossmann fold
Homologous superfamily homologous superfamily	2020 —

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Unit-cell length a length_a	39.500 Å
Unit-cell length b length_b	102.100 Å
Unit-cell length c length_c	51.800 Å
Unit-cell angle α angle_alpha	90.00 °
Unit-cell angle β angle_beta	94.30 °
Unit-cell angle γ angle_gamma	90.00 °
Molecules per unit cell Z z_pdb	4

Space group space_group	P 1 21 1
Space-group number int_tables_number	4
Crystal system crystal_system	—

Resolution resolution	2.000 Å
Low-resolution limit resolution_low	20.000 Å
R factor r_factor	0.2100
R_work r_work	0.2100
R_free r_free	0.2930

Hypoxanthine Phosphoribosyltransferase from Trypanosoma cruzi, K68R mutant, ternary substrates complex

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

hypoxanthine phosphoribosyltransferase

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

1p18__assembly_1__model_1

1p18__assembly_1__model_1 | I(q)

1p18__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 (5)

Entity 1 Entity 1 polymer

Polymer Polymer

Source Source

Entity 2 Entity 2 non-polymer

Entity 3 Entity 3 non-polymer

Entity 4 Entity 4 non-polymer

Entity 5 Entity 5 water

6. Fold Classification (SCOP + CATH) 4 domains

SCOP 2.08 (2 domains)

CATH v4.4 (2 domains)

7. Citations (1)

Hypoxanthine Phosphoribosyltransferase from Trypanosoma cruzi, K68R mutant, ternary substrates complex

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

hypoxanthine phosphoribosyltransferase

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

1p18__assembly_1__model_1

1p18__assembly_1__model_1 | I(q)

1p18__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 (5)

Entity 1 Entity 1 polymer

Polymer Polymer

Source Source

Entity 2 Entity 2 non-polymer

Entity 3 Entity 3 non-polymer

Entity 4 Entity 4 non-polymer

Entity 5 Entity 5 water

6. Fold Classification (SCOP + CATH) 4 domains

SCOP 2.08 (2 domains)

CATH v4.4 (2 domains)

7. Citations (1)