3t0b

E. coli (LacZ) beta-galactosidase (S796T) IPTG complex

Method: X-RAY DIFFRACTION

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

Beta-galactosidase

Escherichia coli

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein homooligomer	Homooligomer	Protein 4	MAGNESIUM ION × 8 SODIUM ION × 14 1-methylethyl 1-thio-beta-D-galactopyranoside × 4 DIMETHYL SULFOXIDE × 69 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 38–1052； UniProt 10–1024 Author chain B； PDBConstruct 38–1052； UniProt 10–1024 Author chain C； PDBConstruct 38–1052； UniProt 10–1024 Author chain D； PDBConstruct 38–1052； UniProt 10–1024

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	3t0b
Deposition date deposition_date	2011-07-19
Structure title title	E. coli (LacZ) beta-galactosidase (S796T) IPTG complex
Keywords keywords	Dynampic Loop Conformation, Ser-796, TIM BARREL (ALPHA/BETA BARREL), JELLY-ROLL BARREL, BETA SUPERSANDWICH, GLYCOSIDASE, 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.

3t0b__assembly_1__model_1

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

Download this curve (.dat)

3t0b__assembly_1__model_1 | I(q)

100 plotted points; both axes use logarithmic scales.

3t0b__assembly_1__model_1 | P(r) · Pending

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

Rg（Guinier）	52.04 Å
Rg (electron density)	51.68 Å
Total Rg	51.88 Å
Atom count	32983
Residues	4059
Excluded volume	580760 Å³
Maximum q	0.500 Å⁻¹

Assembly	Model	Structure unit	Oligomeric description	Status	CRYSOL	Actions
1	1	`3t0b__assembly_1__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 (6)

Entity 1 Entity 1 polymer

Description description	Beta-galactosidase
Molecular weight formula_weight	119757.8 kDa
EC 编号 ec_number	3.2.1.23
Mutation mutation	S796T
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	36706

MGGSHHHHHHGMASMTGGQQMGRDLYDDDDKDPMIDPVVLQRRDWENPGVTQLNRLAAHPPFASWRNSEEARTDRPSQQLRSLNGEWRFAWFPAPEAVPESWLECDLPEADTVVVPSNWQMHGYDAPIYTNVTYPITVNPPFVPTENPTGCYSLTFNVDESWLQEGQTRIIFDGVNSAFHLWCNGRWVGYGQDSRLPSEFDLSAFLRAGENRLAVMVLRWSDGSYLEDQDMWRMSGIFRDVSLLHKPTTQISDFHVATRFNDDFSRAVLEAEVQMCGELRDYLRVTVSLWQGETQVASGTAPFGGEIIDERGGYADRVTLRLNVENPKLWSAEIPNLYRAVVELHTADGTLIEAEACDVGFREVRIENGLLLLNGKPLLIRGVNRHEHHPLHGQVMDEQTMVQDILLMKQNNFNAVRCSHYPNHPLWYTLCDRYGLYVVDEANIETHGMVPMNRLTDDPRWLPAMSERVTRMVQRDRNHPSVIIWSLGNESGHGANHDALYRWIKSVDPSRPVQYEGGGADTTATDIICPMYARVDEDQPFPAVPKWSIKKWLSLPGETRPLILCEYAHAMGNSLGGFAKYWQAFRQYPRLQGGFVWDWVDQSLIKYDENGNPWSAYGGDFGDTPNDRQFCMNGLVFADRTPHPALTEAKHQQQFFQFRLSGQTIEVTSEYLFRHSDNELLHWMVALDGKPLASGEVPLDVAPQGKQLIELPELPQPESAGQLWLTVRVVQPNATAWSEAGHISAWQQWRLAENLSVTLPAASHAIPHLTTSEMDFCIELGNKRWQFNRQSGFLSQMWIGDKKQLLTPLRDQFTRAPLDNDIGVTEATRIDPNAWVERWKAAGHYQAEAALLQCTADTLADAVLITTAHAWQHQGKTLFISRKTYRIDGSGQMAITVDVEVASDTPHPARIGLNCQLAQVAERVNWLGLGPQENYPDRLTAACFDRWDLPLSDMYTPYVFPSENGLRCGTRELNYGPHQWRGDFQFNISRYSQQQLMETSHRHLLHAEEGTWLNIDGFHMGIGGDDSWSPSVSAEFQLSAGRYHYQLVWCQK

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	MAGNESIUM ION
Molecular weight formula_weight	24.3 kDa
Source method src_method	syn
Copy count entity_count	8

Entity 3 Entity 3 non-polymer

Description description	SODIUM ION
Molecular weight formula_weight	23.0 kDa
Source method src_method	syn
Copy count entity_count	14

Entity 4 Entity 4 non-polymer

Description description	1-methylethyl 1-thio-beta-D-galactopyranoside
Molecular weight formula_weight	238.3 kDa
Source method src_method	syn
Copy count entity_count	4

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	69

Entity 6 Entity 6 water

Description description	water
Molecular weight formula_weight	18.0 kDa
Source method src_method	nat
Copy count entity_count	3723

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6. Fold Classification (SCOP + CATH) 40 domains

SCOP 2.08 (20 domains)

Domain ID domain_id	d3t0ba1
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.18.1.0 — automated matches

Domain ID domain_id	d3t0ba2
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.1.4.0 — automated matches

Domain ID domain_id	d3t0ba3
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.1.8.0 — automated matches

Domain ID domain_id	d3t0ba4
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.1.4.0 — automated matches

Domain ID domain_id	d3t0ba5
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.30.5.0 — automated matches

Domain ID domain_id	d3t0bb1
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.18.1.0 — automated matches

Domain ID domain_id	d3t0bb2
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.1.4.0 — automated matches

Domain ID domain_id	d3t0bb3
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.1.8.0 — automated matches

Domain ID domain_id	d3t0bb4
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.1.4.0 — automated matches

Domain ID domain_id	d3t0bb5
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.30.5.0 — automated matches

Domain ID domain_id	d3t0bc1
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.18.1.0 — automated matches

Domain ID domain_id	d3t0bc2
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.1.4.0 — automated matches

Domain ID domain_id	d3t0bc3
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.1.8.0 — automated matches

Domain ID domain_id	d3t0bc4
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.1.4.0 — automated matches

Domain ID domain_id	d3t0bc5
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.30.5.0 — automated matches

Domain ID domain_id	d3t0bd1
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.18.1.0 — automated matches

Domain ID domain_id	d3t0bd2
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.1.4.0 — automated matches

Domain ID domain_id	d3t0bd3
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.1.8.0 — automated matches

Domain ID domain_id	d3t0bd4
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.1.4.0 — automated matches

Domain ID domain_id	d3t0bd5
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.30.5.0 — automated matches

CATH v4.4 (20 domains)

Domain ID domain_id	3t0bA01
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	120 — Jelly Rolls
Homologous superfamily homologous superfamily	260 — Galactose-binding domain-like

Domain ID domain_id	3t0bA02
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	10 — Immunoglobulins

Domain ID domain_id	3t0bA03
Class class	3 — Alpha Beta
Architecture architecture	20 — Alpha-Beta Barrel
Topology topology	20 — TIM Barrel
Homologous superfamily homologous superfamily	80 — Glycosidases

Domain ID domain_id	3t0bA04
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	10 — Immunoglobulins

Domain ID domain_id	3t0bA05
Class class	2 — Mainly Beta
Architecture architecture	70 — Distorted Sandwich
Topology topology	98 — Beta-galactosidase; Chain A, domain 5
Homologous superfamily homologous superfamily	10 —

Domain ID domain_id	3t0bB01
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	120 — Jelly Rolls
Homologous superfamily homologous superfamily	260 — Galactose-binding domain-like

Domain ID domain_id	3t0bB02
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	10 — Immunoglobulins

Domain ID domain_id	3t0bB03
Class class	3 — Alpha Beta
Architecture architecture	20 — Alpha-Beta Barrel
Topology topology	20 — TIM Barrel
Homologous superfamily homologous superfamily	80 — Glycosidases

Domain ID domain_id	3t0bB04
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	10 — Immunoglobulins

Domain ID domain_id	3t0bB05
Class class	2 — Mainly Beta
Architecture architecture	70 — Distorted Sandwich
Topology topology	98 — Beta-galactosidase; Chain A, domain 5
Homologous superfamily homologous superfamily	10 —

Domain ID domain_id	3t0bC01
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	120 — Jelly Rolls
Homologous superfamily homologous superfamily	260 — Galactose-binding domain-like

Domain ID domain_id	3t0bC02
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	10 — Immunoglobulins

Domain ID domain_id	3t0bC03
Class class	3 — Alpha Beta
Architecture architecture	20 — Alpha-Beta Barrel
Topology topology	20 — TIM Barrel
Homologous superfamily homologous superfamily	80 — Glycosidases

Domain ID domain_id	3t0bC04
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	10 — Immunoglobulins

Domain ID domain_id	3t0bC05
Class class	2 — Mainly Beta
Architecture architecture	70 — Distorted Sandwich
Topology topology	98 — Beta-galactosidase; Chain A, domain 5
Homologous superfamily homologous superfamily	10 —

Domain ID domain_id	3t0bD01
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	120 — Jelly Rolls
Homologous superfamily homologous superfamily	260 — Galactose-binding domain-like

Domain ID domain_id	3t0bD02
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	10 — Immunoglobulins

Domain ID domain_id	3t0bD03
Class class	3 — Alpha Beta
Architecture architecture	20 — Alpha-Beta Barrel
Topology topology	20 — TIM Barrel
Homologous superfamily homologous superfamily	80 — Glycosidases

Domain ID domain_id	3t0bD04
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	10 — Immunoglobulins

Domain ID domain_id	3t0bD05
Class class	2 — Mainly Beta
Architecture architecture	70 — Distorted Sandwich
Topology topology	98 — Beta-galactosidase; Chain A, domain 5
Homologous superfamily homologous superfamily	10 —

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Unit-cell length a length_a	151.970 Å
Unit-cell length b length_b	163.140 Å
Unit-cell length c length_c	204.020 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	2.400 Å
Low-resolution limit resolution_low	67.790 Å
R factor r_factor	0.1659
R_work r_work	0.1649
R_free r_free	0.2328

E. coli (LacZ) beta-galactosidase (S796T) IPTG complex

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

3t0b__assembly_1__model_1

3t0b__assembly_1__model_1 | I(q)

3t0b__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 (6)

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 water

6. Fold Classification (SCOP + CATH) 40 domains

SCOP 2.08 (20 domains)

CATH v4.4 (20 domains)

7. Citations (1)

E. coli (LacZ) beta-galactosidase (S796T) IPTG complex

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

3t0b__assembly_1__model_1

3t0b__assembly_1__model_1 | I(q)

3t0b__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 (6)

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 water

6. Fold Classification (SCOP + CATH) 40 domains

SCOP 2.08 (20 domains)

CATH v4.4 (20 domains)

7. Citations (1)