25ii

Cryo-EM structure of human Nav1.6 in complex with Iota-Conotoxin RXIA

Method: ELECTRON MICROSCOPY

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

Sodium channel protein type 8 subunit alpha

Homo sapiens

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Other combination	Heteromer	Protein 3 其他Polymer 2	Sodium channel regulatory subunit beta-1 × 1 （Q07699） Iota-conotoxin RXIA × 1 （Q7Z094） ;alpha-D-mannopyranose-(1-2)-alpha-D-mannopyranose-(1-6)-[alpha-D-mannopyranose-(1-3)]alpha-D-mannopyranose-(1-6)-[alpha-D-mannopyranose-(1-2)-alpha-D-mannopyranose-(1-3)]beta-D-mannopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-3)-2-acetamido-2-deoxy-beta-D-glucopyranose ; × 1 2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose × 1 2-acetamido-2-deoxy-beta-D-glucopyranose × 7 (3beta,14beta,17beta,25R)-3-[4-methoxy-3-(methoxymethyl)butoxy]spirost-5-en × 1 1,2-DIOLEOYL-SN-GLYCERO-3-PHOSPHOCHOLINE × 5 CHOLESTEROL HEMISUCCINATE × 3 CHOLESTEROL × 1 O-[(R)-{[(2R)-2,3-bis(octadecanoyloxy)propyl]oxy}(hydroxy)phosphoryl]-L-serine × 1 1-O-OCTADECYL-SN-GLYCERO-3-PHOSPHOCHOLINE × 1 (5E,17R,20S)-23-amino-20-hydroxy-14,20-dioxo-15,19,21-trioxa-20lambda~5~-phosphatricos-5-en-17-yl hexadecanoate × 1 SODIUM ION × 1 water × 3	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	SCN8A_HUMAN
Isoform	—
PDB entities	1
Chains and sequence ranges	Author chain A； PDBConstruct 1–1980； UniProt 1–1980

Sodium channel regulatory subunit beta-1

Homo sapiens

UniProt Q07699

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Other combination	Heteromer	Protein 3 其他Polymer 2	Sodium channel protein type 8 subunit alpha × 1 （Q9UQD0） Iota-conotoxin RXIA × 1 （Q7Z094） ;alpha-D-mannopyranose-(1-2)-alpha-D-mannopyranose-(1-6)-[alpha-D-mannopyranose-(1-3)]alpha-D-mannopyranose-(1-6)-[alpha-D-mannopyranose-(1-2)-alpha-D-mannopyranose-(1-3)]beta-D-mannopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-3)-2-acetamido-2-deoxy-beta-D-glucopyranose ; × 1 2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose × 1 2-acetamido-2-deoxy-beta-D-glucopyranose × 7 (3beta,14beta,17beta,25R)-3-[4-methoxy-3-(methoxymethyl)butoxy]spirost-5-en × 1 1,2-DIOLEOYL-SN-GLYCERO-3-PHOSPHOCHOLINE × 5 CHOLESTEROL HEMISUCCINATE × 3 CHOLESTEROL × 1 O-[(R)-{[(2R)-2,3-bis(octadecanoyloxy)propyl]oxy}(hydroxy)phosphoryl]-L-serine × 1 1-O-OCTADECYL-SN-GLYCERO-3-PHOSPHOCHOLINE × 1 (5E,17R,20S)-23-amino-20-hydroxy-14,20-dioxo-15,19,21-trioxa-20lambda~5~-phosphatricos-5-en-17-yl hexadecanoate × 1 SODIUM ION × 1 water × 3	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	SCN1B_HUMAN
Isoform	—
PDB entities	2
Chains and sequence ranges	Author chain C； PDBConstruct 1–218； UniProt 1–218

Iota-conotoxin RXIA

Conus radiatus

UniProt Q7Z094

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Other combination	Heteromer	Protein 3 其他Polymer 2	Sodium channel protein type 8 subunit alpha × 1 （Q9UQD0） Sodium channel regulatory subunit beta-1 × 1 （Q07699） ;alpha-D-mannopyranose-(1-2)-alpha-D-mannopyranose-(1-6)-[alpha-D-mannopyranose-(1-3)]alpha-D-mannopyranose-(1-6)-[alpha-D-mannopyranose-(1-2)-alpha-D-mannopyranose-(1-3)]beta-D-mannopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-3)-2-acetamido-2-deoxy-beta-D-glucopyranose ; × 1 2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose × 1 2-acetamido-2-deoxy-beta-D-glucopyranose × 7 (3beta,14beta,17beta,25R)-3-[4-methoxy-3-(methoxymethyl)butoxy]spirost-5-en × 1 1,2-DIOLEOYL-SN-GLYCERO-3-PHOSPHOCHOLINE × 5 CHOLESTEROL HEMISUCCINATE × 3 CHOLESTEROL × 1 O-[(R)-{[(2R)-2,3-bis(octadecanoyloxy)propyl]oxy}(hydroxy)phosphoryl]-L-serine × 1 1-O-OCTADECYL-SN-GLYCERO-3-PHOSPHOCHOLINE × 1 (5E,17R,20S)-23-amino-20-hydroxy-14,20-dioxo-15,19,21-trioxa-20lambda~5~-phosphatricos-5-en-17-yl hexadecanoate × 1 SODIUM ION × 1 water × 3	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	I1BA_CONRA
Isoform	—
PDB entities	3
Chains and sequence ranges	Author chain D； PDBConstruct 1–46； UniProt 1–46

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	25ii
Deposition date deposition_date	2026-04-06
Structure title title	Cryo-EM structure of human Nav1.6 in complex with Iota-Conotoxin RXIA
Keywords keywords	Nav1.6, voltage gated sodium channel, cryo-EM, toxin, Iota-Conotoxin RXIA, TRANSPORT PROTEIN-TOXIN complex, MEMBRANE PROTEIN; MEMBRANE PROTEIN
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.

25ii__assembly_1__model_1

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

Download this curve (.dat)

25ii__assembly_1__model_1 | I(q)

100 plotted points; both axes use logarithmic scales.

25ii__assembly_1__model_1 | P(r) · Pending

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

Rg（Guinier）	40.77 Å
Rg (electron density)	40.01 Å
Total Rg	40.20 Å
Atom count	12601
Residues	1469
Excluded volume	231660 Å³
Maximum q	0.500 Å⁻¹

Assembly	Model	Structure unit	Oligomeric description	Status	CRYSOL	Actions
1	1	`25ii__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 (15)

Entity 1 Entity 1 polymer

Description description	Sodium channel protein type 8 subunit alpha
Molecular weight formula_weight	225520.6 kDa
Source method src_method	man
Copy count entity_count	1

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	A
Atom count atom_count	12629

MAARLLAPPGPDSFKPFTPESLANIERRIAESKLKKPPKADGSHREDDEDSKPKPNSDLEAGKSLPFIYGDIPQGLVAVPLEDFDPYYLTQKTFVVLNRGKTLFRFSATPALYILSPFNLIRRIAIKILIHSVFSMIIMCTILTNCVFMTFSNPPDWSKNVEYTFTGIYTFESLVKIIARGFCIDGFTFLRDPWNWLDFSVIMMAYITEFVNLGNVSALRTFRVLRALKTISVIPGLKTIVGALIQSVKKLSDVMILTVFCLSVFALIGLQLFMGNLRNKCVVWPINFNESYLENGTKGFDWEEYINNKTNFYTVPGMLEPLLCGNSSDAGQCPEGYQCMKAGRNPNYGYTSFDTFSWAFLALFRLMTQDYWENLYQLTLRAAGKTYMIFFVLVIFVGSFYLVNLILAVVAMAYEEQNQATLEEAEQKEAEFKAMLEQLKKQQEEAQAAAMATSAGTVSEDAIEEEGEEGGGSPRSSSEISKLSSKSAKERRNRRKKRKQKELSEGEEKGDPEKVFKSESEDGMRRKAFRLPDNRIGRKFSIMNQSLLSIPGSPFLSRHNSKSSIFSFRGPGRFRDPGSENEFADDEHSTVEESEGRRDSLFIPIRARERRSSYSGYSGYSQGSRSSRIFPSLRRSVKRNSTVDCNGVVSLIGGPGSHIGGRLLPEATTEVEIKKKGPGSLLVSMDQLASYGRKDRINSIMSVVTNTLVEELEESQRKCPPCWYKFANTFLIWECHPYWIKLKEIVNLIVMDPFVDLAITICIVLNTLFMAMEHHPMTPQFEHVLAVGNLVFTGIFTAEMFLKLIAMDPYYYFQEGWNIFDGFIVSLSLMELSLADVEGLSVLRSFRLLRVFKLAKSWPTLNMLIKIIGNSVGALGNLTLVLAIIVFIFAVVGMQLFGKSYKECVCKINQDCELPRWHMHDFFHSFLIVFRVLCGEWIETMWDCMEVAGQAMCLIVFMMVMVIGNLVVLNLFLALLLSSFSADNLAATDDDGEMNNLQISVIRIKKGVAWTKLKVHAFMQAHFKQREADEVKPLDELYEKKANCIANHTGADIHRNGDFQKNGNGTTSGIGSSVEKYIIDEDHMSFINNPNLTVRVPIAVGESDFENLNTEDVSSESDPEGSKDKLDDTSSSEGSTIDIKPEVEEVPVEQPEEYLDPDACFTEGCVQRFKCCQVNIEEGLGKSWWILRKTCFLIVEHNWFETFIIFMILLSSGALAFEDIYIEQRKTIRTILEYADKVFTYIFILEMLLKWTAYGFVKFFTNAWCWLDFLIVAVSLVSLIANALGYSELGAIKSLRTLRALRPLRALSRFEGMRVVVNALVGAIPSIMNVLLVCLIFWLIFSIMGVNLFAGKYHYCFNETSEIRFEIEDVNNKTECEKLMEGNNTEIRWKNVKINFDNVGAGYLALLQVATFKGWMDIMYAAVDSRKPDEQPKYEDNIYMYIYFVIFIIFGSFFTLNLFIGVIIDNFNQQKKKFGGQDIFMTEEQKKYYNAMKKLGSKKPQKPIPRPLNKIQGIVFDFVTQQAFDIVIMMLICLNMVTMMVETDTQSKQMENILYWINLVFVIFFTCECVLKMFALRHYYFTIGWNIFDFVVVILSIVGMFLADIIEKYFVSPTLFRVIRLARIGRILRLIKGAKGIRTLLFALMMSLPALFNIGLLLFLVMFIFSIFGMSNFAYVKHEAGIDDMFNFETFGNSMICLFQITTSAGWDGLLLPILNRPPDCSLDKEHPGSGFKGDCGNPSVGIFFFVSYIIISFLIVVNMYIAIILENFSVATEESADPLSEDDFETFYEIWEKFDPDATQFIEYCKLADFADALEHPLRVPKPNTIELIAMDLPMVSGDRIHCLDILFAFTKRVLGDSGELDILRQQMEERFVASNPSKVSYEPITTTLRRKQEEVSAVVLQRAYRGHLARRGFICKKTTSNKLENGGTHREKKESTPSTASLPSYDSVTKPEKEKQQRAEEGRRERAKRQKEVRESKC

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	Sodium channel regulatory subunit beta-1
Molecular weight formula_weight	24732.1 kDa
Source method src_method	man
Copy count entity_count	1

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	C

MGRLLALVVGAALVSSACGGCVEVDSETEAVYGMTFKILCISCKRRSETNAETFTEWTFRQKGTEEFVKILRYENEVLQLEEDERFEGRVVWNGSRGTKDLQDLSIFITNVTYNHSGDYECHVYRLLFFENYEHNTSVVKKIHIEVVDKANRDMASIVSEIMMYVLIVVLTIWLVAEMIYCYKKIAAATETAAQENASEYLAITSESKENCTGVQVAE

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	Iota-conotoxin RXIA
Molecular weight formula_weight	4987.7 kDa
Source method src_method	man
Copy count entity_count	1

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	D

GPSFCKADEKPCEYHADCCNCCLSGICAPSTNWILPGCSTSSFFKI

Source Source

Source organism organism	Conus radiatus
NCBI taxonomy ID ncbi_taxonomy_id	61198
Host organism host_organism	Conus radiatus

Entity 4 Entity 4 branched

Description description	;alpha-D-mannopyranose-(1-2)-alpha-D-mannopyranose-(1-6)-[alpha-D-mannopyranose-(1-3)]alpha-D-mannopyranose-(1-6)-[alpha-D-mannopyranose-(1-2)-alpha-D-mannopyranose-(1-3)]beta-D-mannopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-3)-2-acetamido-2-deoxy-beta-D-glucopyranose ;
Molecular weight formula_weight	1559.4 kDa
Source method src_method	man
Copy count entity_count	1

Entity 5 Entity 5 branched

Description description	2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose
Molecular weight formula_weight	424.4 kDa
Source method src_method	man
Copy count entity_count	1

Entity 6 Entity 6 non-polymer

Description description	2-acetamido-2-deoxy-beta-D-glucopyranose
Molecular weight formula_weight	221.2 kDa
Source method src_method	syn
Copy count entity_count	7

Entity 7 Entity 7 non-polymer

Description description	(3beta,14beta,17beta,25R)-3-[4-methoxy-3-(methoxymethyl)butoxy]spirost-5-en
Molecular weight formula_weight	544.8 kDa
Source method src_method	syn
Copy count entity_count	1

Entity 8 Entity 8 non-polymer

Description description	1,2-DIOLEOYL-SN-GLYCERO-3-PHOSPHOCHOLINE
Molecular weight formula_weight	787.1 kDa
Source method src_method	syn
Copy count entity_count	5

Entity 9 Entity 9 non-polymer

Description description	CHOLESTEROL HEMISUCCINATE
Molecular weight formula_weight	486.7 kDa
Source method src_method	syn
Copy count entity_count	3

Entity 10 Entity 10 non-polymer

Description description	CHOLESTEROL
Molecular weight formula_weight	386.7 kDa
Source method src_method	syn
Copy count entity_count	1

Entity 11 Entity 11 non-polymer

Description description	O-[(R)-{[(2R)-2,3-bis(octadecanoyloxy)propyl]oxy}(hydroxy)phosphoryl]-L-serine
Molecular weight formula_weight	792.1 kDa
Source method src_method	syn
Copy count entity_count	1

Entity 12 Entity 12 non-polymer

Description description	1-O-OCTADECYL-SN-GLYCERO-3-PHOSPHOCHOLINE
Molecular weight formula_weight	510.7 kDa
Source method src_method	syn
Copy count entity_count	1

Entity 13 Entity 13 non-polymer

Description description	(5E,17R,20S)-23-amino-20-hydroxy-14,20-dioxo-15,19,21-trioxa-20lambda~5~-phosphatricos-5-en-17-yl hexadecanoate
Molecular weight formula_weight	661.9 kDa
Source method src_method	syn
Copy count entity_count	1

Entity 14 Entity 14 non-polymer

Description description	SODIUM ION
Molecular weight formula_weight	23.0 kDa
Source method src_method	syn
Copy count entity_count	1

Entity 15 Entity 15 water

Description description	water
Molecular weight formula_weight	18.0 kDa
Source method src_method	nat
Copy count entity_count	28

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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	2.500 Å
Low-resolution limit resolution_low	— Å
R factor r_factor	—
R_work r_work	—
R_free r_free	—

Resolution resolution	2.50 Å
Resolution测定Method resolution_method	—
颗粒数 num_particles	179486

Cryo-EM structure of human Nav1.6 in complex with Iota-Conotoxin RXIA

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

Sodium channel protein type 8 subunit alpha

State in the Current Structure

Other States of the Same Protein in the Database

Monomer

Homodimer

Homotetramer

Other homooligomers

Heteromeric or nucleic-acid complex

Sodium channel regulatory subunit beta-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

Iota-conotoxin RXIA

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

25ii__assembly_1__model_1

25ii__assembly_1__model_1 | I(q)

25ii__assembly_1__model_1 | P(r) · Pending

4. Crystallography and Experiment 4. Crystallography & Experiment

Unit cell Unit Cell

Symmetry Symmetry

Refinement Refinement

冷冻电镜 EM 3D

5. Entities and Polymers Entities & Polymers (15)

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 branched

Entity 5 Entity 5 branched

Entity 6 Entity 6 non-polymer

Entity 7 Entity 7 non-polymer

Entity 8 Entity 8 non-polymer

Entity 9 Entity 9 non-polymer

Entity 10 Entity 10 non-polymer

Entity 11 Entity 11 non-polymer

Entity 12 Entity 12 non-polymer

Entity 13 Entity 13 non-polymer

Entity 14 Entity 14 non-polymer

Entity 15 Entity 15 water

7. Citations (1)