SAXSdb — 4l41

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

Alpha-lactalbumin

Homo sapiens

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein heterocomplex	Heteromer	Protein 3	Beta-1,4-galactosyltransferase 1 × 1 （P15291） CALCIUM ION × 2 SULFATE ION × 1 water × 3	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	LALBA_HUMAN
Isoform	—
PDB entities	1
Chains and sequence ranges	Author chain A； PDBConstruct 1–124； UniProt 19–142 Author chain B； PDBConstruct 1–124； UniProt 19–142

Beta-1,4-galactosyltransferase 1

Homo sapiens

UniProt P15291

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein heterocomplex	Heteromer	Protein 3	Alpha-lactalbumin × 2 （P00709） CALCIUM ION × 2 SULFATE ION × 1 water × 3	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	B4GT1_HUMAN
Isoform	—
PDB entities	2
Chains and sequence ranges	Author chain C； PDBConstruct 15–287； UniProt 126–398

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	4l41
Deposition date deposition_date	2013-06-07
Structure title title	Human Lactose synthase: A 2:1 complex between human alpha-lactalbumin and human beta1,4-galactosyltransferase
Keywords keywords	GT-A fold, lactose synthase, Substrate binding, Golgi, Calcium Binding Protein-Transferase complex; Calcium Binding Protein/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.

4l41__assembly_1__model_1

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

Download this curve (.dat)

4l41__assembly_1__model_1 | I(q)

100 plotted points; both axes use logarithmic scales.

4l41__assembly_1__model_1 | P(r) · Pending

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

Rg（Guinier）	25.13 Å
Rg (electron density)	24.18 Å
Total Rg	25.17 Å
Atom count	4172
Residues	518
Excluded volume	74408 Å³
Maximum q	0.500 Å⁻¹

Assembly	Model	Structure unit	Oligomeric description	Status	CRYSOL	Actions
1	1	`4l41__assembly_1__model_1`	trimeric （3）	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	Alpha-lactalbumin
Molecular weight formula_weight	14164.2 kDa
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	4203

AKQFTKCELSQLLKDIDGYGGIALPELICTMFHTSGYDTQAIVENNESTEYGLFQISNKLWCKSSQVPQSRNICDISCDKFLDDDITDDIMCAKKILDIKGIDYWLAHKALCTEKLEQWLCEKL

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 polymer

Description description	Beta-1,4-galactosyltransferase 1
Molecular weight formula_weight	32766.3 kDa
EC 编号 ec_number	2.4.1.22
Mutation mutation	R337T, C338T
Source method src_method	man
Copy count entity_count	1

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	C

ASMTGGQQMGRGSASLPACPEESPLLVGPMLIEFNMPVDLELVAKQNPNVKMGGRYAPRDCVSPHKVAIIIPFRNRQEHLKYWLYYLHPVLQRQQLDYGIYVINQAGDTIFNRAKLLNVGFQEALKDYDYTCFVFSDVDLIPMNDHNAYRCFSQPRHISVAMDKFGFSLPYVQYFGGVSALSKQQFLTINGFPNNYWGWGGEDDDIFNRLVFRGMSISRPNAVVGTTRMIRHSRDKKNEPNPQRFDRIAHTKETMLSDGLNSLTYQVLDVQRYPLYTQITVDIGTPS

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 3 Entity 3 non-polymer

Description description	CALCIUM ION
Molecular weight formula_weight	40.1 kDa
Source method src_method	syn
Copy count entity_count	2

Entity 4 Entity 4 non-polymer

Description description	SULFATE ION
Molecular weight formula_weight	96.1 kDa
Source method src_method	syn
Copy count entity_count	1

Entity 5 Entity 5 water

Description description	water
Molecular weight formula_weight	18.0 kDa
Source method src_method	nat
Copy count entity_count	31

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6. Fold Classification (SCOP + CATH) 6 domains

SCOP 2.08 (3 domains)

Domain ID domain_id	d4l41a_
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.2 — Lysozyme-like
Superfamily Superfamily superfamily	d.2.1 — Lysozyme-like
Family Family family	d.2.1.0 — automated matches

Domain ID domain_id	d4l41b_
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.2 — Lysozyme-like
Superfamily Superfamily superfamily	d.2.1 — Lysozyme-like
Family Family family	d.2.1.0 — automated matches

Domain ID domain_id	d4l41c_
Class class	c — Alpha and beta proteins (a/b)
Fold Fold fold	c.68 — Nucleotide-diphospho-sugar transferases
Superfamily Superfamily superfamily	c.68.1 — Nucleotide-diphospho-sugar transferases
Family Family family	c.68.1.2 — beta 1,4 galactosyltransferase (b4GalT1)

CATH v4.4 (3 domains)

Domain ID domain_id	4l41A00
Class class	1 — Mainly Alpha
Architecture architecture	10 — Orthogonal Bundle
Topology topology	530 — Lysozyme
Homologous superfamily homologous superfamily	10 —

Domain ID domain_id	4l41B00
Class class	1 — Mainly Alpha
Architecture architecture	10 — Orthogonal Bundle
Topology topology	530 — Lysozyme
Homologous superfamily homologous superfamily	10 —

Domain ID domain_id	4l41C00
Class class	3 — Alpha Beta
Architecture architecture	90 — Alpha-Beta Complex
Topology topology	550 — Spore Coat Polysaccharide Biosynthesis Protein SpsA; Chain A
Homologous superfamily homologous superfamily	10 — Spore Coat Polysaccharide Biosynthesis Protein SpsA; Chain A

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Unit-cell length a length_a	62.390 Å
Unit-cell length b length_b	65.210 Å
Unit-cell length c length_c	71.720 Å
Unit-cell angle α angle_alpha	90.00 °
Unit-cell angle β angle_beta	114.45 °
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	2.700 Å
Low-resolution limit resolution_low	19.521 Å
R factor r_factor	0.1903
R_work r_work	0.1878
R_free r_free	0.2370

Human Lactose synthase: A 2:1 complex between human alpha-lactalbumin and human beta1,4-galactosyltransferase

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

Alpha-lactalbumin

State in the Current Structure

Other States of the Same Protein in the Database

Beta-1,4-galactosyltransferase 1

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

4l41__assembly_1__model_1

4l41__assembly_1__model_1 | I(q)

4l41__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 polymer

Polymer Polymer

Source Source

Entity 3 Entity 3 non-polymer

Entity 4 Entity 4 non-polymer

Entity 5 Entity 5 water

6. Fold Classification (SCOP + CATH) 6 domains

SCOP 2.08 (3 domains)

CATH v4.4 (3 domains)

7. Citations (1)

Human Lactose synthase: A 2:1 complex between human alpha-lactalbumin and human beta1,4-galactosyltransferase

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

Alpha-lactalbumin

State in the Current Structure

Other States of the Same Protein in the Database

Monomer

Homodimer

Homotetramer

Other homooligomers

Heteromeric or nucleic-acid complex

Beta-1,4-galactosyltransferase 1

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

4l41__assembly_1__model_1

4l41__assembly_1__model_1 | I(q)

4l41__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 polymer

Polymer Polymer

Source Source

Entity 3 Entity 3 non-polymer

Entity 4 Entity 4 non-polymer

Entity 5 Entity 5 water

6. Fold Classification (SCOP + CATH) 6 domains

SCOP 2.08 (3 domains)

CATH v4.4 (3 domains)

7. Citations (1)