7btk

E.coli beta-galactosidase (E537Q) in complex with fluorescent probe KSA01

Method: X-RAY DIFFRACTION

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

Beta-galactosidase

Escherichia coli K-12

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein homooligomer	Homooligomer	Protein 4	;4-[[2-[(E)-2-[4-[(2S,3R,4S,5R,6R)-6-(hydroxymethyl)-3,4,5-tris(oxidanyl)oxan-2-yl]oxyphenyl]ethenyl]-3,3-dimethyl-2H-indol-1-yl]methyl]benzoic acid ; × 4 MAGNESIUM ION × 8 SODIUM ION × 8 DIMETHYL SULFOXIDE × 40 water × 4	Consistent with protein count
2	Protein homooligomer	Homooligomer	Protein 4	;4-[[2-[(E)-2-[4-[(2S,3R,4S,5R,6R)-6-(hydroxymethyl)-3,4,5-tris(oxidanyl)oxan-2-yl]oxyphenyl]ethenyl]-3,3-dimethyl-2H-indol-1-yl]methyl]benzoic acid ; × 4 MAGNESIUM ION × 6 SODIUM ION × 6 DIMETHYL SULFOXIDE × 36 GLYCEROL × 2 water × 4	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	BGAL_ECOLI
Isoform	—
PDB entities	1
Chains and sequence ranges	Author chain A； PDBConstruct 2–1025； UniProt 1–1024 Author chain B； PDBConstruct 2–1025； UniProt 1–1024 Author chain C； PDBConstruct 2–1025； UniProt 1–1024 Author chain D； PDBConstruct 2–1025； UniProt 1–1024

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	7btk
Deposition date deposition_date	2020-04-01
Structure title title	E.coli beta-galactosidase (E537Q) in complex with fluorescent probe KSA01
Keywords keywords	beta_galactosidase, fluorescent probe, hydrolase; 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.

7btk__assembly_1__model_1

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

Download this curve (.dat)

7btk__assembly_1__model_1 | I(q)

100 plotted points; both axes use logarithmic scales.

7btk__assembly_1__model_1 | P(r) · Pending

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

Rg（Guinier）	52.03 Å
Rg (electron density)	51.65 Å
Total Rg	51.86 Å
Atom count	32776
Residues	4088
Excluded volume	576350 Å³
Maximum q	0.500 Å⁻¹

Assembly	Model	Structure unit	Oligomeric description	Status	CRYSOL	Actions
1	1	`7btk__assembly_1__model_1`	tetrameric （4）	Success	4.1.3-1-20251215 (887e7ef)	View Download
2	1	`7btk__assembly_2__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 (7)

Entity 1 Entity 1 polymer

Description description	Beta-galactosidase
Molecular weight formula_weight	116688.5 kDa
EC 编号 ec_number	3.2.1.23
Mutation mutation	E537Q
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	33869

SMTMITDSLAVVLQRRDWENPGVTQLNRLAAHPPFASWRNSEEARTDRPSQQLRSLNGEWRFAWFPAPEAVPESWLECDLPEADTVVVPSNWQMHGYDAPIYTNVTYPITVNPPFVPTENPTGCYSLTFNVDESWLQEGQTRIIFDGVNSAFHLWCNGRWVGYGQDSRLPSEFDLSAFLRAGENRLAVMVLRWSDGSYLEDQDMWRMSGIFRDVSLLHKPTTQISDFHVATRFNDDFSRAVLEAEVQMCGELRDYLRVTVSLWQGETQVASGTAPFGGEIIDERGGYADRVTLRLNVENPKLWSAEIPNLYRAVVELHTADGTLIEAEACDVGFREVRIENGLLLLNGKPLLIRGVNRHEHHPLHGQVMDEQTMVQDILLMKQNNFNAVRCSHYPNHPLWYTLCDRYGLYVVDEANIETHGMVPMNRLTDDPRWLPAMSERVTRMVQRDRNHPSVIIWSLGNESGHGANHDALYRWIKSVDPSRPVQYEGGGADTTATDIICPMYARVDEDQPFPAVPKWSIKKWLSLPGETRPLILCQYAHAMGNSLGGFAKYWQAFRQYPRLQGGFVWDWVDQSLIKYDENGNPWSAYGGDFGDTPNDRQFCMNGLVFADRTPHPALTEAKHQQQFFQFRLSGQTIEVTSEYLFRHSDNELLHWMVALDGKPLASGEVPLDVAPQGKQLIELPELPQPESAGQLWLTVRVVQPNATAWSEAGHISAWQQWRLAENLSVTLPAASHAIPHLTTSEMDFCIELGNKRWQFNRQSGFLSQMWIGDKKQLLTPLRDQFTRAPLDNDIGVSEATRIDPNAWVERWKAAGHYQAEAALLQCTADTLADAVLITTAHAWQHQGKTLFISRKTYRIDGSGQMAITVDVEVASDTPHPARIGLNCQLAQVAERVNWLGLGPQENYPDRLTAACFDRWDLPLSDMYTPYVFPSENGLRCGTRELNYGPHQWRGDFQFNISRYSQQQLMETSHRHLLHAEEGTWLNIDGFHMGIGGDDSWSPSVSAEFQLSAGRYHYQLVWCQK

Source Source

Source organism organism	Escherichia coli K-12
NCBI taxonomy ID ncbi_taxonomy_id	83333
Host organism host_organism	Escherichia coli

Entity 2 Entity 2 non-polymer

Description description	;4-[[2-[(E)-2-[4-[(2S,3R,4S,5R,6R)-6-(hydroxymethyl)-3,4,5-tris(oxidanyl)oxan-2-yl]oxyphenyl]ethenyl]-3,3-dimethyl-2H-indol-1-yl]methyl]benzoic acid ;
Molecular weight formula_weight	560.6 kDa
Source method src_method	syn
Copy count entity_count	4

Entity 3 Entity 3 non-polymer

Description description	MAGNESIUM ION
Molecular weight formula_weight	24.3 kDa
Source method src_method	syn
Copy count entity_count	7

Entity 4 Entity 4 non-polymer

Description description	SODIUM ION
Molecular weight formula_weight	23.0 kDa
Source method src_method	syn
Copy count entity_count	7

Entity 5 Entity 5 non-polymer

Description description	DIMETHYL SULFOXIDE
Molecular weight formula_weight	78.1 kDa
Source method src_method	syn
Copy count entity_count	38

Entity 6 Entity 6 non-polymer

Description description	GLYCEROL
Molecular weight formula_weight	92.1 kDa
Source method src_method	syn
Copy count entity_count	1

Entity 7 Entity 7 water

Description description	water
Molecular weight formula_weight	18.0 kDa
Source method src_method	nat
Copy count entity_count	1124

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6. Fold Classification (SCOP + CATH) 20 domains

SCOP 2.08 (20 domains)

Domain ID domain_id	d7btka1
Class class	b — All beta proteins
Fold Fold fold	b.18 — Galactose-binding domain-like
Superfamily Superfamily superfamily	b.18.1 — Galactose-binding domain-like
Family Family family	b.18.1.5 — beta-Galactosidase/glucuronidase, N-terminal domain

Domain ID domain_id	d7btka2
Class class	b — All beta proteins
Fold Fold fold	b.1 — Immunoglobulin-like beta-sandwich
Superfamily Superfamily superfamily	b.1.4 — beta-Galactosidase/glucuronidase domain
Family Family family	b.1.4.1 — beta-Galactosidase/glucuronidase domain

Domain ID domain_id	d7btka3
Class class	c — Alpha and beta proteins (a/b)
Fold Fold fold	c.1 — TIM beta/alpha-barrel
Superfamily Superfamily superfamily	c.1.8 — (Trans)glycosidases
Family Family family	c.1.8.3 — beta-glycanases

Domain ID domain_id	d7btka4
Class class	b — All beta proteins
Fold Fold fold	b.1 — Immunoglobulin-like beta-sandwich
Superfamily Superfamily superfamily	b.1.4 — beta-Galactosidase/glucuronidase domain
Family Family family	b.1.4.1 — beta-Galactosidase/glucuronidase domain

Domain ID domain_id	d7btka5
Class class	b — All beta proteins
Fold Fold fold	b.30 — Supersandwich
Superfamily Superfamily superfamily	b.30.5 — Galactose mutarotase-like
Family Family family	b.30.5.1 — beta-Galactosidase, domain 5

Domain ID domain_id	d7btkb1
Class class	b — All beta proteins
Fold Fold fold	b.18 — Galactose-binding domain-like
Superfamily Superfamily superfamily	b.18.1 — Galactose-binding domain-like
Family Family family	b.18.1.5 — beta-Galactosidase/glucuronidase, N-terminal domain

Domain ID domain_id	d7btkb2
Class class	b — All beta proteins
Fold Fold fold	b.1 — Immunoglobulin-like beta-sandwich
Superfamily Superfamily superfamily	b.1.4 — beta-Galactosidase/glucuronidase domain
Family Family family	b.1.4.1 — beta-Galactosidase/glucuronidase domain

Domain ID domain_id	d7btkb3
Class class	c — Alpha and beta proteins (a/b)
Fold Fold fold	c.1 — TIM beta/alpha-barrel
Superfamily Superfamily superfamily	c.1.8 — (Trans)glycosidases
Family Family family	c.1.8.3 — beta-glycanases

Domain ID domain_id	d7btkb4
Class class	b — All beta proteins
Fold Fold fold	b.1 — Immunoglobulin-like beta-sandwich
Superfamily Superfamily superfamily	b.1.4 — beta-Galactosidase/glucuronidase domain
Family Family family	b.1.4.1 — beta-Galactosidase/glucuronidase domain

Domain ID domain_id	d7btkb5
Class class	b — All beta proteins
Fold Fold fold	b.30 — Supersandwich
Superfamily Superfamily superfamily	b.30.5 — Galactose mutarotase-like
Family Family family	b.30.5.1 — beta-Galactosidase, domain 5

Domain ID domain_id	d7btkc1
Class class	b — All beta proteins
Fold Fold fold	b.18 — Galactose-binding domain-like
Superfamily Superfamily superfamily	b.18.1 — Galactose-binding domain-like
Family Family family	b.18.1.5 — beta-Galactosidase/glucuronidase, N-terminal domain

Domain ID domain_id	d7btkc2
Class class	b — All beta proteins
Fold Fold fold	b.1 — Immunoglobulin-like beta-sandwich
Superfamily Superfamily superfamily	b.1.4 — beta-Galactosidase/glucuronidase domain
Family Family family	b.1.4.1 — beta-Galactosidase/glucuronidase domain

Domain ID domain_id	d7btkc3
Class class	c — Alpha and beta proteins (a/b)
Fold Fold fold	c.1 — TIM beta/alpha-barrel
Superfamily Superfamily superfamily	c.1.8 — (Trans)glycosidases
Family Family family	c.1.8.3 — beta-glycanases

Domain ID domain_id	d7btkc4
Class class	b — All beta proteins
Fold Fold fold	b.1 — Immunoglobulin-like beta-sandwich
Superfamily Superfamily superfamily	b.1.4 — beta-Galactosidase/glucuronidase domain
Family Family family	b.1.4.1 — beta-Galactosidase/glucuronidase domain

Domain ID domain_id	d7btkc5
Class class	b — All beta proteins
Fold Fold fold	b.30 — Supersandwich
Superfamily Superfamily superfamily	b.30.5 — Galactose mutarotase-like
Family Family family	b.30.5.1 — beta-Galactosidase, domain 5

Domain ID domain_id	d7btkd1
Class class	b — All beta proteins
Fold Fold fold	b.18 — Galactose-binding domain-like
Superfamily Superfamily superfamily	b.18.1 — Galactose-binding domain-like
Family Family family	b.18.1.5 — beta-Galactosidase/glucuronidase, N-terminal domain

Domain ID domain_id	d7btkd2
Class class	b — All beta proteins
Fold Fold fold	b.1 — Immunoglobulin-like beta-sandwich
Superfamily Superfamily superfamily	b.1.4 — beta-Galactosidase/glucuronidase domain
Family Family family	b.1.4.1 — beta-Galactosidase/glucuronidase domain

Domain ID domain_id	d7btkd3
Class class	c — Alpha and beta proteins (a/b)
Fold Fold fold	c.1 — TIM beta/alpha-barrel
Superfamily Superfamily superfamily	c.1.8 — (Trans)glycosidases
Family Family family	c.1.8.3 — beta-glycanases

Domain ID domain_id	d7btkd4
Class class	b — All beta proteins
Fold Fold fold	b.1 — Immunoglobulin-like beta-sandwich
Superfamily Superfamily superfamily	b.1.4 — beta-Galactosidase/glucuronidase domain
Family Family family	b.1.4.1 — beta-Galactosidase/glucuronidase domain

Domain ID domain_id	d7btkd5
Class class	b — All beta proteins
Fold Fold fold	b.30 — Supersandwich
Superfamily Superfamily superfamily	b.30.5 — Galactose mutarotase-like
Family Family family	b.30.5.1 — beta-Galactosidase, domain 5

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Unit-cell length a length_a	249.832 Å
Unit-cell length b length_b	85.454 Å
Unit-cell length c length_c	243.307 Å
Unit-cell angle α angle_alpha	90.00 °
Unit-cell angle β angle_beta	94.15 °
Unit-cell angle γ angle_gamma	90.00 °
Molecules per unit cell Z z_pdb	16

Space group space_group	C 1 2 1
Space-group number int_tables_number	5
Crystal system crystal_system	—

Resolution resolution	2.700 Å
Low-resolution limit resolution_low	19.870 Å
R factor r_factor	0.2185
R_work r_work	0.2177
R_free r_free	0.2332

E.coli beta-galactosidase (E537Q) in complex with fluorescent probe KSA01

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

Beta-galactosidase

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

7btk__assembly_1__model_1

7btk__assembly_1__model_1 | I(q)

7btk__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 (7)

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 non-polymer

Entity 6 Entity 6 non-polymer

Entity 7 Entity 7 water

6. Fold Classification (SCOP + CATH) 20 domains

SCOP 2.08 (20 domains)

7. Citations (1)

E.coli beta-galactosidase (E537Q) in complex with fluorescent probe KSA01

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

Beta-galactosidase

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

7btk__assembly_1__model_1

7btk__assembly_1__model_1 | I(q)

7btk__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 (7)

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 non-polymer

Entity 6 Entity 6 non-polymer

Entity 7 Entity 7 water

6. Fold Classification (SCOP + CATH) 20 domains

SCOP 2.08 (20 domains)

7. Citations (1)