1q12

Crystal Structure of the ATP-bound E. coli MalK

Method: X-RAY DIFFRACTION

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

Maltose/maltodextrin transport ATP-binding protein malK

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	ADENOSINE-5'-TRIPHOSPHATE × 2	Consistent with protein count
2	Protein homooligomer	Homooligomer	Protein 2	ADENOSINE-5'-TRIPHOSPHATE × 2 water × 2	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	MALK_ECOLI
Isoform	—
PDB entities	1
Chains and sequence ranges	Author chain A； PDBConstruct 1–371； UniProt 1–371 Author chain B； PDBConstruct 1–371； UniProt 1–371 Author chain C； PDBConstruct 1–371； UniProt 1–371 Author chain D； PDBConstruct 1–371； UniProt 1–371

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	1q12
Deposition date deposition_date	2003-07-18
Structure title title	Crystal Structure of the ATP-bound E. coli MalK
Keywords keywords	ATP-binding cassette, transport protein; TRANSPORT PROTEIN
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.

1q12__assembly_1__model_1

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

Download this curve (.dat)

1q12__assembly_1__model_1 | I(q)

100 plotted points; both axes use logarithmic scales.

1q12__assembly_1__model_1 | P(r) · Pending

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

Rg（Guinier）	27.88 Å
Rg (electron density)	26.84 Å
Total Rg	27.68 Å
Atom count	5768
Residues	734
Excluded volume	102930 Å³
Maximum q	0.500 Å⁻¹

Assembly	Model	Structure unit	Oligomeric description	Status	CRYSOL	Actions
1	1	`1q12__assembly_1__model_1`	dimeric （2）	Success	4.1.3-1-20251215 (887e7ef)	View Download
2	1	`1q12__assembly_2__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	Maltose/maltodextrin transport ATP-binding protein malK
Molecular weight formula_weight	42184.5 kDa
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	11546

MASVQLQNVTKAWGEVVVSKDINLDIHEGEFVVFVGPSGCGKSTLLRMIAGLETITSGDLFIGEKRMNDTPPAERGVGMVFQSYALYPHLSVAENMSFGLKLAGAKKEVINQRVNQVAEVLQLAHLLDRKPKALSGGQRQRVAIGRTLVAEPSVFLLDEPLSNLDAALRVQMRIEISRLHKRLGRTMIYVTHDQVEAMTLADKIVVLDAGRVAQVGKPLELYHYPADRFVAGFIGSPKMNFLPVKVTATAIDQVQVELPMPNRQQVWLPVESRDVQVGANMSLGIRPEHLLPSDIADVILEGEVQVVEQLGNETQIHIQIPSIRQNLVYRQNDVVLVEEGATFAIGLPPERCHLFREDGTACRRLHKEPGVASASHHHHHH

Source Source

Source organism organism	Escherichia coli
NCBI taxonomy ID ncbi_taxonomy_id	83333
Host organism host_organism	Escherichia coli

Entity 2 Entity 2 non-polymer

Description description	ADENOSINE-5'-TRIPHOSPHATE
Molecular weight formula_weight	507.2 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	10

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6. Fold Classification (SCOP + CATH) 20 domains

SCOP 2.08 (8 domains)

Domain ID domain_id	d1q12a1
Class class	b — All beta proteins
Fold Fold fold	b.40 — OB-fold
Superfamily Superfamily superfamily	b.40.6 — MOP-like
Family Family family	b.40.6.3 — ABC-transporter additional domain

Domain ID domain_id	d1q12a2
Class class	c — Alpha and beta proteins (a/b)
Fold Fold fold	c.37 — P-loop containing nucleoside triphosphate hydrolases
Superfamily Superfamily superfamily	c.37.1 — P-loop containing nucleoside triphosphate hydrolases
Family Family family	c.37.1.12 — ABC transporter ATPase domain-like

Domain ID domain_id	d1q12b1
Class class	b — All beta proteins
Fold Fold fold	b.40 — OB-fold
Superfamily Superfamily superfamily	b.40.6 — MOP-like
Family Family family	b.40.6.3 — ABC-transporter additional domain

Domain ID domain_id	d1q12b2
Class class	c — Alpha and beta proteins (a/b)
Fold Fold fold	c.37 — P-loop containing nucleoside triphosphate hydrolases
Superfamily Superfamily superfamily	c.37.1 — P-loop containing nucleoside triphosphate hydrolases
Family Family family	c.37.1.12 — ABC transporter ATPase domain-like

Domain ID domain_id	d1q12c1
Class class	b — All beta proteins
Fold Fold fold	b.40 — OB-fold
Superfamily Superfamily superfamily	b.40.6 — MOP-like
Family Family family	b.40.6.3 — ABC-transporter additional domain

Domain ID domain_id	d1q12c2
Class class	c — Alpha and beta proteins (a/b)
Fold Fold fold	c.37 — P-loop containing nucleoside triphosphate hydrolases
Superfamily Superfamily superfamily	c.37.1 — P-loop containing nucleoside triphosphate hydrolases
Family Family family	c.37.1.12 — ABC transporter ATPase domain-like

Domain ID domain_id	d1q12d1
Class class	b — All beta proteins
Fold Fold fold	b.40 — OB-fold
Superfamily Superfamily superfamily	b.40.6 — MOP-like
Family Family family	b.40.6.3 — ABC-transporter additional domain

Domain ID domain_id	d1q12d2
Class class	c — Alpha and beta proteins (a/b)
Fold Fold fold	c.37 — P-loop containing nucleoside triphosphate hydrolases
Superfamily Superfamily superfamily	c.37.1 — P-loop containing nucleoside triphosphate hydrolases
Family Family family	c.37.1.12 — ABC transporter ATPase domain-like

CATH v4.4 (12 domains)

Domain ID domain_id	1q12A01
Class class	3 — Alpha Beta
Architecture architecture	40 — 3-Layer(aba) Sandwich
Topology topology	50 — Rossmann fold
Homologous superfamily homologous superfamily	300 — P-loop containing nucleotide triphosphate hydrolases

Domain ID domain_id	1q12A02
Class class	2 — Mainly Beta
Architecture architecture	40 — Beta Barrel
Topology topology	50 — OB fold (Dihydrolipoamide Acetyltransferase, E2P)
Homologous superfamily homologous superfamily	140 — Nucleic acid-binding proteins

Domain ID domain_id	1q12A03
Class class	2 — Mainly Beta
Architecture architecture	40 — Beta Barrel
Topology topology	50 — OB fold (Dihydrolipoamide Acetyltransferase, E2P)
Homologous superfamily homologous superfamily	100 — RNA polymerase II/Efflux pump adaptor protein, barrel-sandwich hybrid domain

Domain ID domain_id	1q12B01
Class class	3 — Alpha Beta
Architecture architecture	40 — 3-Layer(aba) Sandwich
Topology topology	50 — Rossmann fold
Homologous superfamily homologous superfamily	300 — P-loop containing nucleotide triphosphate hydrolases

Domain ID domain_id	1q12B02
Class class	2 — Mainly Beta
Architecture architecture	40 — Beta Barrel
Topology topology	50 — OB fold (Dihydrolipoamide Acetyltransferase, E2P)
Homologous superfamily homologous superfamily	140 — Nucleic acid-binding proteins

Domain ID domain_id	1q12B03
Class class	2 — Mainly Beta
Architecture architecture	40 — Beta Barrel
Topology topology	50 — OB fold (Dihydrolipoamide Acetyltransferase, E2P)
Homologous superfamily homologous superfamily	100 — RNA polymerase II/Efflux pump adaptor protein, barrel-sandwich hybrid domain

Domain ID domain_id	1q12C01
Class class	3 — Alpha Beta
Architecture architecture	40 — 3-Layer(aba) Sandwich
Topology topology	50 — Rossmann fold
Homologous superfamily homologous superfamily	300 — P-loop containing nucleotide triphosphate hydrolases

Domain ID domain_id	1q12C02
Class class	2 — Mainly Beta
Architecture architecture	40 — Beta Barrel
Topology topology	50 — OB fold (Dihydrolipoamide Acetyltransferase, E2P)
Homologous superfamily homologous superfamily	140 — Nucleic acid-binding proteins

Domain ID domain_id	1q12C03
Class class	2 — Mainly Beta
Architecture architecture	40 — Beta Barrel
Topology topology	50 — OB fold (Dihydrolipoamide Acetyltransferase, E2P)
Homologous superfamily homologous superfamily	100 — RNA polymerase II/Efflux pump adaptor protein, barrel-sandwich hybrid domain

Domain ID domain_id	1q12D01
Class class	3 — Alpha Beta
Architecture architecture	40 — 3-Layer(aba) Sandwich
Topology topology	50 — Rossmann fold
Homologous superfamily homologous superfamily	300 — P-loop containing nucleotide triphosphate hydrolases

Domain ID domain_id	1q12D02
Class class	2 — Mainly Beta
Architecture architecture	40 — Beta Barrel
Topology topology	50 — OB fold (Dihydrolipoamide Acetyltransferase, E2P)
Homologous superfamily homologous superfamily	140 — Nucleic acid-binding proteins

Domain ID domain_id	1q12D03
Class class	2 — Mainly Beta
Architecture architecture	40 — Beta Barrel
Topology topology	50 — OB fold (Dihydrolipoamide Acetyltransferase, E2P)
Homologous superfamily homologous superfamily	100 — RNA polymerase II/Efflux pump adaptor protein, barrel-sandwich hybrid domain

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Unit-cell length a length_a	59.880 Å
Unit-cell length b length_b	97.278 Å
Unit-cell length c length_c	101.862 Å
Unit-cell angle α angle_alpha	74.59 °
Unit-cell angle β angle_beta	82.47 °
Unit-cell angle γ angle_gamma	76.85 °
Molecules per unit cell Z z_pdb	4

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

Resolution resolution	2.600 Å
Low-resolution limit resolution_low	14.800 Å
R factor r_factor	0.2580
R_work r_work	0.2580
R_free r_free	0.2860

Crystal Structure of the ATP-bound E. coli MalK

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

Maltose/maltodextrin transport ATP-binding protein malK

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

1q12__assembly_1__model_1

1q12__assembly_1__model_1 | I(q)

1q12__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) 20 domains

SCOP 2.08 (8 domains)

CATH v4.4 (12 domains)

7. Citations (1)

Crystal Structure of the ATP-bound E. coli MalK

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

Maltose/maltodextrin transport ATP-binding protein malK

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

1q12__assembly_1__model_1

1q12__assembly_1__model_1 | I(q)

1q12__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) 20 domains

SCOP 2.08 (8 domains)

CATH v4.4 (12 domains)

7. Citations (1)