SAXSdb — 1a4i

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

METHYLENETETRAHYDROFOLATE DEHYDROGENASE / METHENYLTETRAHYDROFOLATE CYCLOHYDROLASE

Homo sapiens

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein homooligomer	Homooligomer	Protein 2	NADPH DIHYDRO-NICOTINAMIDE-ADENINE-DINUCLEOTIDE PHOSPHATE × 2 water × 2	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	C1TC_HUMAN
Isoform	—
PDB entities	1
Chains and sequence ranges	Author chain A； PDBConstruct 2–301； UniProt 1–300 Author chain B； PDBConstruct 2–301； UniProt 1–300

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	1a4i
Deposition date deposition_date	1998-01-30
Structure title title	HUMAN TETRAHYDROFOLATE DEHYDROGENASE / CYCLOHYDROLASE
Keywords keywords	THF, BIFUNCTIONAL, DEHYDROGENASE, CYCLOHYDROLASE, FOLATE, OXIDOREDUCTASE; OXIDOREDUCTASE
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.

1a4i__assembly_1__model_1

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

Download this curve (.dat)

1a4i__assembly_1__model_1 | I(q)

100 plotted points; both axes use logarithmic scales.

1a4i__assembly_1__model_1 | P(r) · Pending

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

Rg（Guinier）	26.28 Å
Rg (electron density)	25.46 Å
Total Rg	26.20 Å
Atom count	4492
Residues	580
Excluded volume	80099 Å³
Maximum q	0.500 Å⁻¹

Assembly	Model	Structure unit	Oligomeric description	Status	CRYSOL	Actions
1	1	`1a4i__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 (3)

Entity 1 Entity 1 polymer

Description description	METHYLENETETRAHYDROFOLATE DEHYDROGENASE / METHENYLTETRAHYDROFOLATE CYCLOHYDROLASE
Molecular weight formula_weight	32650.5 kDa
EC 编号 ec_number	1.5.1.5, 3.5.4.9
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	4899

MAPAEILNGKEISAQIRARLKNQVTQLKEQVPGFTPRLAILQVGNRDDSNLYINVKLKAAEEIGIKATHIKLPRTTTESEVMKYITSLNEDSTVHGFLVQLPLDSENSINTEEVINAIAPEKDVDGLTSINAGRLARGDLNDCFIPCTPKGCLELIKETGVPIAGRHAVVVGRSKIVGAPMHDLLLWNNATVTTCHSKTAHLDEEVNKGDILVVATGQPEMVKGEWIKPGAIVIDCGINYVPDDKKPNGRKVVGDVAYDEAKERASFITPVPGGVGPMTVAMLMQSTVESAKRFLEKFKPG

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	NADPH DIHYDRO-NICOTINAMIDE-ADENINE-DINUCLEOTIDE PHOSPHATE
Molecular weight formula_weight	745.4 kDa
Source method src_method	syn
Copy count entity_count	2

Entity 3 Entity 3 water

Description description	water
Molecular weight formula_weight	18.0 kDa
Source method src_method	nat
Copy count entity_count	407

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6. Fold Classification (SCOP + CATH) 8 domains

SCOP 2.08 (4 domains)

Domain ID domain_id	d1a4ia1
Class class	c — Alpha and beta proteins (a/b)
Fold Fold fold	c.2 — NAD(P)-binding Rossmann-fold domains
Superfamily Superfamily superfamily	c.2.1 — NAD(P)-binding Rossmann-fold domains
Family Family family	c.2.1.7 — Aminoacid dehydrogenase-like, C-terminal domain

Domain ID domain_id	d1a4ia2
Class class	c — Alpha and beta proteins (a/b)
Fold Fold fold	c.58 — Aminoacid dehydrogenase-like, N-terminal domain
Superfamily Superfamily superfamily	c.58.1 — Aminoacid dehydrogenase-like, N-terminal domain
Family Family family	c.58.1.2 — Tetrahydrofolate dehydrogenase/cyclohydrolase

Domain ID domain_id	d1a4ib1
Class class	c — Alpha and beta proteins (a/b)
Fold Fold fold	c.2 — NAD(P)-binding Rossmann-fold domains
Superfamily Superfamily superfamily	c.2.1 — NAD(P)-binding Rossmann-fold domains
Family Family family	c.2.1.7 — Aminoacid dehydrogenase-like, C-terminal domain

Domain ID domain_id	d1a4ib2
Class class	c — Alpha and beta proteins (a/b)
Fold Fold fold	c.58 — Aminoacid dehydrogenase-like, N-terminal domain
Superfamily Superfamily superfamily	c.58.1 — Aminoacid dehydrogenase-like, N-terminal domain
Family Family family	c.58.1.2 — Tetrahydrofolate dehydrogenase/cyclohydrolase

CATH v4.4 (4 domains)

Domain ID domain_id	1a4iA01
Class class	3 — Alpha Beta
Architecture architecture	40 — 3-Layer(aba) Sandwich
Topology topology	50 — Rossmann fold
Homologous superfamily homologous superfamily	720 — NAD(P)-binding Rossmann-like Domain

Domain ID domain_id	1a4iA02
Class class	3 — Alpha Beta
Architecture architecture	40 — 3-Layer(aba) Sandwich
Topology topology	50 — Rossmann fold
Homologous superfamily homologous superfamily	10860 — Leucine Dehydrogenase, chain A, domain 1

Domain ID domain_id	1a4iB01
Class class	3 — Alpha Beta
Architecture architecture	40 — 3-Layer(aba) Sandwich
Topology topology	50 — Rossmann fold
Homologous superfamily homologous superfamily	720 — NAD(P)-binding Rossmann-like Domain

Domain ID domain_id	1a4iB02
Class class	3 — Alpha Beta
Architecture architecture	40 — 3-Layer(aba) Sandwich
Topology topology	50 — Rossmann fold
Homologous superfamily homologous superfamily	10860 — Leucine Dehydrogenase, chain A, domain 1

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Unit-cell length a length_a	67.523 Å
Unit-cell length b length_b	135.843 Å
Unit-cell length c length_c	61.403 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	8

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

Resolution resolution	1.500 Å
Low-resolution limit resolution_low	20.000 Å
R factor r_factor	—
R_work r_work	0.1990
R_free r_free	0.2350

HUMAN TETRAHYDROFOLATE DEHYDROGENASE / CYCLOHYDROLASE

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

METHYLENETETRAHYDROFOLATE DEHYDROGENASE / METHENYLTETRAHYDROFOLATE CYCLOHYDROLASE

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

1a4i__assembly_1__model_1

1a4i__assembly_1__model_1 | I(q)

1a4i__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) 8 domains

SCOP 2.08 (4 domains)

CATH v4.4 (4 domains)

7. Citations (1)

HUMAN TETRAHYDROFOLATE DEHYDROGENASE / CYCLOHYDROLASE

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

METHYLENETETRAHYDROFOLATE DEHYDROGENASE / METHENYLTETRAHYDROFOLATE CYCLOHYDROLASE

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

1a4i__assembly_1__model_1

1a4i__assembly_1__model_1 | I(q)

1a4i__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) 8 domains

SCOP 2.08 (4 domains)

CATH v4.4 (4 domains)

7. Citations (1)