1ktl

The human non-classical major histocompatibility complex molecule HLA-E

Method: X-RAY DIFFRACTION

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

HLA CLASS I HISTOCOMPATIBILITY ANTIGEN, ALPHA CHAIN

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-2-MICROGLOBULIN × 1 （P01884） Peptide VTAPRTLLL × 1 SULFATE ION × 1	Consistent with protein count
2	Protein heterocomplex	Heteromer	Protein 3	BETA-2-MICROGLOBULIN × 1 （P01884） Peptide VTAPRTLLL × 1	Consistent with protein count
3	Protein heterocomplex	Heteromer	Protein 12	BETA-2-MICROGLOBULIN × 4 （P01884） Peptide VTAPRTLLL × 4 SULFATE ION × 2	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	HLAE_HUMAN
Isoform	—
PDB entities	1
Chains and sequence ranges	Author chain A； PDBConstruct 1–274； UniProt 22–295 Author chain C； PDBConstruct 1–274； UniProt 22–295

BETA-2-MICROGLOBULIN

Homo sapiens

UniProt P01884

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein heterocomplex	Heteromer	Protein 3	HLA CLASS I HISTOCOMPATIBILITY ANTIGEN, ALPHA CHAIN × 1 （P13747） Peptide VTAPRTLLL × 1 SULFATE ION × 1	Consistent with protein count
2	Protein heterocomplex	Heteromer	Protein 3	HLA CLASS I HISTOCOMPATIBILITY ANTIGEN, ALPHA CHAIN × 1 （P13747） Peptide VTAPRTLLL × 1	Consistent with protein count
3	Protein heterocomplex	Heteromer	Protein 12	HLA CLASS I HISTOCOMPATIBILITY ANTIGEN, ALPHA CHAIN × 4 （P13747） Peptide VTAPRTLLL × 4 SULFATE ION × 2	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	B2MG_HUMAN
Isoform	—
PDB entities	2
Chains and sequence ranges	Author chain B； PDBConstruct 2–100； UniProt 21–119 Author chain D； PDBConstruct 2–100； UniProt 21–119

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	1ktl
Deposition date deposition_date	2002-01-16
Structure title title	The human non-classical major histocompatibility complex molecule HLA-E
Keywords keywords	HLA-E, MHC, NON-CLASSICAL MHC, HLA, BETA 2 MICROGLOBULIN, IMMUNE SYSTEM; IMMUNE SYSTEM
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.

1ktl__assembly_1__model_1

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

Download this curve (.dat)

1ktl__assembly_1__model_1 | I(q)

100 plotted points; both axes use logarithmic scales.

1ktl__assembly_1__model_1 | P(r) · Pending

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

Rg（Guinier）	24.13 Å
Rg (electron density)	22.93 Å
Total Rg	23.74 Å
Atom count	3102
Residues	383
Excluded volume	54081 Å³
Maximum q	0.500 Å⁻¹

Assembly	Model	Structure unit	Oligomeric description	Status	CRYSOL	Actions
1	1	`1ktl__assembly_1__model_1`	trimeric （3）	Success	4.1.3-1-20251215 (887e7ef)	View Download
2	1	`1ktl__assembly_2__model_1`	trimeric （3）	Success	4.1.3-1-20251215 (887e7ef)	View Download
3	1	`1ktl__assembly_3__model_1`	dodecameric （12）	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 (4)

Entity 1 Entity 1 polymer

Description description	HLA CLASS I HISTOCOMPATIBILITY ANTIGEN, ALPHA CHAIN
Molecular weight formula_weight	31511.6 kDa
Mutation mutation	R107G
Source method src_method	man
Copy count entity_count	2

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	A,C
Atom count atom_count	6211

GSHSLKYFHTSVSRPGRGEPRFISVGYVDDTQFVRFDNDAASPRMVPRAPWMEQEGSEYWDRETRSARDTAQIFRVNLRTLRGYYNQSEAGSHTLQWMHGCELGPDGRFLRGYEQFAYDGKDYLTLNEDLRSWTAVDTAAQISEQKSNDASEAEHQRAYLEDTCVEWLHKYLEKGKETLLHLEPPKTHVTHHPISDHEATLRCWALGFYPAEITLTWQQDGEGHTQDTELVETRPAGDGTFQKWAAVVVPSGEEQAYTCHVQHEGLPEPVTLRW

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-2-MICROGLOBULIN
Molecular weight formula_weight	11879.4 kDa
Source method src_method	man
Copy count entity_count	2

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	B,D

MIQRTPKIQVYSRHPAENGKSNFLNCYVSGFHPSDIEVDLLKNGERIEKVEHSDLSFSKDWSFYLLYYTEFTPTEKDEYACRVNHVTLSQPKIVKWDRDM

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 polymer

Description description	Peptide VTAPRTLLL
Molecular weight formula_weight	984.2 kDa
Source method src_method	syn
Copy count entity_count	2

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	P,Q

VTAPRTLLL

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

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6. Fold Classification (SCOP + CATH) 14 domains

SCOP 2.08 (8 domains)

Domain ID domain_id	d1ktla1
Class class	b — All beta proteins
Fold Fold fold	b.1 — Immunoglobulin-like beta-sandwich
Superfamily Superfamily superfamily	b.1.1 — Immunoglobulin
Family Family family	b.1.1.2 — C1 set domains (antibody constant domain-like)

Domain ID domain_id	d1ktla2
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.19 — MHC antigen-recognition domain
Superfamily Superfamily superfamily	d.19.1 — MHC antigen-recognition domain
Family Family family	d.19.1.1 — MHC antigen-recognition domain

Domain ID domain_id	d1ktlb1
Class class	b — All beta proteins
Fold Fold fold	b.1 — Immunoglobulin-like beta-sandwich
Superfamily Superfamily superfamily	b.1.1 — Immunoglobulin
Family Family family	b.1.1.2 — C1 set domains (antibody constant domain-like)

Domain ID domain_id	d1ktlb2
Class class	l — Artifacts
Fold Fold fold	l.1 — Tags
Superfamily Superfamily superfamily	l.1.1 — Tags
Family Family family	l.1.1.1 — Tags

Domain ID domain_id	d1ktlc1
Class class	b — All beta proteins
Fold Fold fold	b.1 — Immunoglobulin-like beta-sandwich
Superfamily Superfamily superfamily	b.1.1 — Immunoglobulin
Family Family family	b.1.1.2 — C1 set domains (antibody constant domain-like)

Domain ID domain_id	d1ktlc2
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.19 — MHC antigen-recognition domain
Superfamily Superfamily superfamily	d.19.1 — MHC antigen-recognition domain
Family Family family	d.19.1.1 — MHC antigen-recognition domain

Domain ID domain_id	d1ktld1
Class class	b — All beta proteins
Fold Fold fold	b.1 — Immunoglobulin-like beta-sandwich
Superfamily Superfamily superfamily	b.1.1 — Immunoglobulin
Family Family family	b.1.1.2 — C1 set domains (antibody constant domain-like)

Domain ID domain_id	d1ktld2
Class class	l — Artifacts
Fold Fold fold	l.1 — Tags
Superfamily Superfamily superfamily	l.1.1 — Tags
Family Family family	l.1.1.1 — Tags

CATH v4.4 (6 domains)

Domain ID domain_id	1ktlA01
Class class	3 — Alpha Beta
Architecture architecture	30 — 2-Layer Sandwich
Topology topology	500 — Murine Class I Major Histocompatibility Complex, H2-DB; Chain A, domain 1
Homologous superfamily homologous superfamily	10 — MHC class I-like antigen recognition-like

Domain ID domain_id	1ktlA02
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	10 — Immunoglobulins

Domain ID domain_id	1ktlB00
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	10 — Immunoglobulins

Domain ID domain_id	1ktlC01
Class class	3 — Alpha Beta
Architecture architecture	30 — 2-Layer Sandwich
Topology topology	500 — Murine Class I Major Histocompatibility Complex, H2-DB; Chain A, domain 1
Homologous superfamily homologous superfamily	10 — MHC class I-like antigen recognition-like

Domain ID domain_id	1ktlC02
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	10 — Immunoglobulins

Domain ID domain_id	1ktlD00
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	10 — Immunoglobulins

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Unit-cell length a length_a	178.400 Å
Unit-cell length b length_b	178.400 Å
Unit-cell length c length_c	87.300 Å
Unit-cell angle α angle_alpha	90.00 °
Unit-cell angle β angle_beta	90.00 °
Unit-cell angle γ angle_gamma	120.00 °
Molecules per unit cell Z z_pdb	12

Space group space_group	P 31 2 1
Space-group number int_tables_number	152
Crystal system crystal_system	—

Resolution resolution	3.100 Å
Low-resolution limit resolution_low	25.000 Å
R factor r_factor	—
R_work r_work	0.2380
R_free r_free	0.2800

The human non-classical major histocompatibility complex molecule HLA-E

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

HLA CLASS I HISTOCOMPATIBILITY ANTIGEN, ALPHA CHAIN

State in the Current Structure

Other States of the Same Protein in the Database

BETA-2-MICROGLOBULIN

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

1ktl__assembly_1__model_1

1ktl__assembly_1__model_1 | I(q)

1ktl__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 (4)

Entity 1 Entity 1 polymer

Polymer Polymer

Source Source

Entity 2 Entity 2 polymer

Polymer Polymer

Source Source

Entity 3 Entity 3 polymer

Polymer Polymer

Entity 4 Entity 4 non-polymer

6. Fold Classification (SCOP + CATH) 14 domains

SCOP 2.08 (8 domains)

CATH v4.4 (6 domains)

7. Citations (1)

The human non-classical major histocompatibility complex molecule HLA-E

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

HLA CLASS I HISTOCOMPATIBILITY ANTIGEN, ALPHA CHAIN

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-2-MICROGLOBULIN

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

1ktl__assembly_1__model_1

1ktl__assembly_1__model_1 | I(q)

1ktl__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 (4)

Entity 1 Entity 1 polymer

Polymer Polymer

Source Source

Entity 2 Entity 2 polymer

Polymer Polymer

Source Source

Entity 3 Entity 3 polymer

Polymer Polymer

Entity 4 Entity 4 non-polymer

6. Fold Classification (SCOP + CATH) 14 domains

SCOP 2.08 (8 domains)

CATH v4.4 (6 domains)

7. Citations (1)