SAXSdb — 6lxw

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

Interleukin-2,Immunoglobulin heavy constant alpha 1

Homo sapiens

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Insufficient information	Heteromer	Protein 7	Immunoglobulin J chain × 1 （P01591） Polymeric immunoglobulin receptor × 1 （P01833） SigA binding protein × 1 （O33753）	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	IGHA1_HUMAN
Isoform	—
PDB entities	1
Chains and sequence ranges	Author chain A； PDBConstruct 60–291； UniProt 122–353 Author chain B； PDBConstruct 60–291； UniProt 122–353 Author chain C； PDBConstruct 60–291； UniProt 122–353 Author chain D； PDBConstruct 60–291； UniProt 122–353

Interleukin-2,Immunoglobulin heavy constant alpha 1

Homo sapiens

UniProt P60568

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Insufficient information	Heteromer	Protein 7	Immunoglobulin J chain × 1 （P01591） Polymeric immunoglobulin receptor × 1 （P01833） SigA binding protein × 1 （O33753）	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	IL2_HUMAN
Isoform	—
PDB entities	1
Chains and sequence ranges	Author chain A； PDBConstruct 1–21； UniProt 1–21 Author chain B； PDBConstruct 1–21； UniProt 1–21 Author chain C； PDBConstruct 1–21； UniProt 1–21 Author chain D； PDBConstruct 1–21； UniProt 1–21

Immunoglobulin J chain

Homo sapiens

UniProt P01591

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Insufficient information	Heteromer	Protein 7	Interleukin-2,Immunoglobulin heavy constant alpha 1 × 4 （P01876,P60568） Polymeric immunoglobulin receptor × 1 （P01833） SigA binding protein × 1 （O33753）	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	IGJ_HUMAN
Isoform	—
PDB entities	2
Chains and sequence ranges	Author chain J； PDBConstruct 1–159； UniProt 1–159

Polymeric immunoglobulin receptor

Homo sapiens

UniProt P01833

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Insufficient information	Heteromer	Protein 7	Interleukin-2,Immunoglobulin heavy constant alpha 1 × 4 （P01876,P60568） Immunoglobulin J chain × 1 （P01591） SigA binding protein × 1 （O33753）	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	PIGR_HUMAN
Isoform	—
PDB entities	3
Chains and sequence ranges	Author chain P； PDBConstruct 1–565； UniProt 1–565

SigA binding protein

Streptococcus pneumoniae

UniProt O33753

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Insufficient information	Heteromer	Protein 7	Interleukin-2,Immunoglobulin heavy constant alpha 1 × 4 （P01876,P60568） Immunoglobulin J chain × 1 （P01591） Polymeric immunoglobulin receptor × 1 （P01833）	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	O33753_STREE
Isoform	—
PDB entities	4
Chains and sequence ranges	Author chain S； PDBConstruct 31–317； UniProt 38–324

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	6lxw
Deposition date deposition_date	2020-02-12
Structure title title	Cryo-EM structure of human secretory immunoglobulin A in complex with the N-terminal domain of SpsA
Keywords keywords	immunoglobulin, dimer, transcytosis, secreted, IMMUNE SYSTEM; IMMUNE SYSTEM
Experimental Method method	ELECTRON MICROSCOPY

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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.

6lxw__assembly_1__model_1

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

Download this curve (.dat)

6lxw__assembly_1__model_1 | I(q)

100 plotted points; both axes use logarithmic scales.

6lxw__assembly_1__model_1 | P(r) · Pending

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

Rg（Guinier）	46.30 Å
Rg (electron density)	46.28 Å
Total Rg	46.42 Å
Atom count	12299
Residues	1595
Excluded volume	218530 Å³
Maximum q	0.500 Å⁻¹

Assembly	Model	Structure unit	Oligomeric description	Status	CRYSOL	Actions
1	1	`6lxw__assembly_1__model_1`	heptameric （7）	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	Interleukin-2,Immunoglobulin heavy constant alpha 1
Molecular weight formula_weight	31445.7 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	12299

MYRMQLLSCIALSLALVTNSARIHMSAWSHPQFEKGGGSGGGSGGSAWSHPQFEKIDTTCCHPRLSLHRPALEDLLLGSEANLTCTLTGLRDASGVTFTWTPSSGKSAVQGPPERDLCGCYSVSSVLPGCAEPWNHGKTFTCTAAYPESKTPLTATLSKSGNTFRPEVHLLPPPSEELALNELVTLTCLARGFSPKDVLVRWLQGSQELPREKYLTWASRQEPSQGTTTFAVTSILRVAAEDWKKGDTFSCMVGHEALPLAFTQKTIDRLAGKPTHVNVSVVMAEVDGTCY

Source Source

Source organism organism	Homo sapiens
Common name common_name	Human
NCBI taxonomy ID ncbi_taxonomy_id	9606
Host organism host_organism	Homo sapiens

Entity 2 Entity 2 polymer

Description description	Immunoglobulin J chain
Molecular weight formula_weight	19225.8 kDa
Source method src_method	man
Copy count entity_count	1

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	J

MKNHLLFWGVLAVFIKAVHVKAQEDERIVLVDNKCKCARITSRIIRSSEDPNEDIVERNIRIIVPLNNRENISDPTSPLRTRFVYHLSDLCKKCDPTEVELDNQIVTATQSNICDEDSATETCYTYDRNKCYTAVVPLVYGGETKMVETALTPDACYPDHHHHHHHH

Source Source

Source organism organism	Homo sapiens
Common name common_name	Human
NCBI taxonomy ID ncbi_taxonomy_id	9606
Host organism host_organism	Homo sapiens

Entity 3 Entity 3 polymer

Description description	Polymeric immunoglobulin receptor
Molecular weight formula_weight	63306.3 kDa
Source method src_method	man
Copy count entity_count	1

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	P

MLLFVLTCLLAVFPAISTKSPIFGPEEVNSVEGNSVSITCYYPPTSVNRHTRKYWCRQGARGGCITLISSEGYVSSKYAGRANLTNFPENGTFVVNIAQLSQDDSGRYKCGLGINSRGLSFDVSLEVSQGPGLLNDTKVYTVDLGRTVTINCPFKTENAQKRKSLYKQIGLYPVLVIDSSGYVNPNYTGRIRLDIQGTGQLLFSVVINQLRLSDAGQYLCQAGDDSNSNKKNADLQVLKPEPELVYEDLRGSVTFHCALGPEVANVAKFLCRQSSGENCDVVVNTLGKRAPAFEGRILLNPQDKDGSFSVVITGLRKEDAGRYLCGAHSDGQLQEGSPIQAWQLFVNEESTIPRSPTVVKGVAGGSVAVLCPYNRKESKSIKYWCLWEGAQNGRCPLLVDSEGWVKAQYEGRLSLLEEPGNGTFTVILNQLTSRDAGFYWCLTNGDTLWRTTVEIKIIEGEPNLKVPGNVTAVLGETLKVPCHFPCKFSSYEKYWCKWNNTGCQALPSQDEGPSKAFVNCDENSRLVSLTLNLVTRADEGWYWCGVKQGHFYGETAAVYVAVEERHHHHHHHH

Source Source

Source organism organism	Homo sapiens
Common name common_name	Human
NCBI taxonomy ID ncbi_taxonomy_id	9606
Host organism host_organism	Homo sapiens

Entity 4 Entity 4 polymer

Description description	SigA binding protein
Molecular weight formula_weight	36311.1 kDa
Source method src_method	man
Copy count entity_count	1

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	S

MGSHHHHHHHHGSDYDIPTTENLYFQGSEFTENEGSTQAATFSNMANKSQTEQGEINIERDKAKTAVSEYKEKKVSEIYTKLERDRHKDTVDLVNKLQEIKNEYLNKIVQSTSKTEIQGLITTSRSKLDEAVSKYKKAPSSSSSSGSSTKPEASDTAKPNKPTELEKKVAEAEKKVEEAKKKAKDQKEEDYRNYPTITYKTLELEIAESDVEVKKAELELVKEEAKEPRNEEKVKQAKAKVESEETEATRLEKIKTDRKKAEEEAKRKAAEEDKVKEKPAEQQAEEDYARRSEEEYNRLTQQQPPKTEKPAQPSTPK

Source Source

Source organism organism	Streptococcus pneumoniae
NCBI taxonomy ID ncbi_taxonomy_id	1313
Host organism host_organism	Escherichia phage Ecwhy_1

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6. Fold Classification (SCOP + CATH) 8 domains

CATH v4.4 (8 domains)

Domain ID domain_id	6lxwA01
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	10 — Immunoglobulins

Domain ID domain_id	6lxwA02
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	10 — Immunoglobulins

Domain ID domain_id	6lxwB01
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	10 — Immunoglobulins

Domain ID domain_id	6lxwB02
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	10 — Immunoglobulins

Domain ID domain_id	6lxwC01
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	10 — Immunoglobulins

Domain ID domain_id	6lxwC02
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	10 — Immunoglobulins

Domain ID domain_id	6lxwD01
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	10 — Immunoglobulins

Domain ID domain_id	6lxwD02
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	1.000 Å
Unit-cell length b length_b	1.000 Å
Unit-cell length c length_c	1.000 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	—

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

Resolution resolution	3.27 Å
Resolution测定Method resolution_method	—
颗粒数 num_particles	280791

Cryo-EM structure of human secretory immunoglobulin A in complex with the N-terminal domain of SpsA

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

Interleukin-2,Immunoglobulin heavy constant alpha 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

Interleukin-2,Immunoglobulin heavy constant alpha 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

Immunoglobulin J 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

Polymeric immunoglobulin receptor

State in the Current Structure

Other States of the Same Protein in the Database

Monomer

Homodimer

Homotetramer

Other homooligomers

Heteromeric or nucleic-acid complex

SigA binding protein

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

6lxw__assembly_1__model_1

6lxw__assembly_1__model_1 | I(q)

6lxw__assembly_1__model_1 | P(r) · Pending

4. Crystallography and Experiment 4. Crystallography & Experiment

Unit cell Unit Cell

Symmetry Symmetry

冷冻电镜 EM 3D

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

Source Source

Entity 4 Entity 4 polymer

Polymer Polymer

Source Source

6. Fold Classification (SCOP + CATH) 8 domains

CATH v4.4 (8 domains)

7. Citations (1)