9n9i

Cryo-EM structure of the Xenopus laevis mitotic centromere-associated kinesin (MCAK) bound to the paclitaxel-stabilized microtubule

Method: ELECTRON MICROSCOPY

▼

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

Tubulin alpha-1B chain

OrganismNot specified

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein heterocomplex	Heteromer	Protein 9	Tubulin beta chain × 4 （P02554） Kinesin-like protein KIF2C × 1 （Q91636） GUANOSINE-5'-TRIPHOSPHATE × 4 MAGNESIUM ION × 8 GUANOSINE-5'-DIPHOSPHATE × 4 TAXOL × 4	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	TBA1B_PIG
Isoform	—
PDB entities	1
Chains and sequence ranges	Author chain 1； PDBConstruct 1–451； UniProt 1–451 Author chain 4； PDBConstruct 1–451； UniProt 1–451 Author chain A； PDBConstruct 1–451； UniProt 1–451 Author chain a； PDBConstruct 1–451； UniProt 1–451

Tubulin beta chain

OrganismNot specified

UniProt P02554

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein heterocomplex	Heteromer	Protein 9	Tubulin alpha-1B chain × 4 （Q2XVP4） Kinesin-like protein KIF2C × 1 （Q91636） GUANOSINE-5'-TRIPHOSPHATE × 4 MAGNESIUM ION × 8 GUANOSINE-5'-DIPHOSPHATE × 4 TAXOL × 4	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	TBB_PIG
Isoform	—
PDB entities	2
Chains and sequence ranges	Author chain 3； PDBConstruct 1–445； UniProt 1–445 Author chain B； PDBConstruct 1–445； UniProt 1–445 Author chain C； PDBConstruct 1–445； UniProt 1–445 Author chain b； PDBConstruct 1–445； UniProt 1–445

Kinesin-like protein KIF2C

Xenopus laevis

UniProt Q91636

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein heterocomplex	Heteromer	Protein 9	Tubulin alpha-1B chain × 4 （Q2XVP4） Tubulin beta chain × 4 （P02554） GUANOSINE-5'-TRIPHOSPHATE × 4 MAGNESIUM ION × 8 GUANOSINE-5'-DIPHOSPHATE × 4 TAXOL × 4	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	KIF2C_XENLA
Isoform	—
PDB entities	3
Chains and sequence ranges	Author chain M； PDBConstruct 1–730； UniProt 1–730

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.

▼

2. Structure Basics 2. Structure Basics

Entry ID entry_id	9n9i
Deposition date deposition_date	2025-02-10
Structure title title	Cryo-EM structure of the Xenopus laevis mitotic centromere-associated kinesin (MCAK) bound to the paclitaxel-stabilized microtubule
Keywords keywords	microtubule, MCAK, kinesin, mitosis, cell cycle; CELL CYCLE
Experimental Method method	ELECTRON MICROSCOPY

▼

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.

9n9i__assembly_1__model_1

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

Download this curve (.dat)

9n9i__assembly_1__model_1 | I(q)

100 plotted points; both axes use logarithmic scales.

9n9i__assembly_1__model_1 | P(r) · Pending

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

Rg（Guinier）	57.81 Å
Rg (electron density)	57.94 Å
Total Rg	57.95 Å
Atom count	30614
Residues	3831
Excluded volume	541040 Å³
Maximum q	0.500 Å⁻¹

Assembly	Model	Structure unit	Oligomeric description	Status	CRYSOL	Actions
1	1	`9n9i__assembly_1__model_1`	nonameric （9）	Success	4.1.3-1-20251215 (887e7ef)	View Download

▶

4. Crystallography and Experiment 4. Crystallography & Experiment

▶

5. Entities and Polymers Entities & Polymers (7)

Entity 1 Entity 1 polymer

Description description	Tubulin alpha-1B chain
Molecular weight formula_weight	50204.4 kDa
Source method src_method	nat
Copy count entity_count	4

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	1,4,A,a
Atom count atom_count	30614

MRECISIHVGQAGVQIGNACWELYCLEHGIQPDGQMPSDKTIGGGDDSFNTFFSETGAGKHVPRAVFVDLEPTVIDEVRTGTYRQLFHPEQLITGKEDAANNYARGHYTIGKEIIDLVLDRIRKLADQCTGLQGFLVFHSFGGGTGSGFTSLLMERLSVDYGKKSKLEFSIYPAPQVSTAVVEPYNSILTTHTTLEHSDCAFMVDNEAIYDICRRNLDIERPTYTNLNRLISQIVSSITASLRFDGALNVDLTEFQTNLVPYPRIHFPLATYAPVISAEKAYHEQLSVAEITNACFEPANQMVKCDPRHGKYMACCLLYRGDVVPKDVNAAIATIKTKRSIQFVDWCPTGFKVGINYQPPTVVPGGDLAKVQRAVCMLSNTTAIAEAWARLDHKFDLMYAKRAFVHWYVGEGMEEGEFSEAREDMAALEKDYEEVGVDSVEGEGEEEGEEY

Entity 2 Entity 2 polymer

Description description	Tubulin beta chain
Molecular weight formula_weight	49907.8 kDa
Source method src_method	nat
Copy count entity_count	4

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	3,B,C,b

MREIVHIQAGQCGNQIGAKFWEVISDEHGIDPTGSYHGDSDLQLERINVYYNEAAGNKYVPRAILVDLEPGTMDSVRSGPFGQIFRPDNFVFGQSGAGNNWAKGHYTEGAELVDSVLDVVRKESESCDCLQGFQLTHSLGGGTGSGMGTLLISKIREEYPDRIMNTFSVVPSPKVSDTVVEPYNATLSVHQLVENTDETYCIDNEALYDICFRTLKLTTPTYGDLNHLVSATMSGVTTCLRFPGQLNADLRKLAVNMVPFPRLHFFMPGFAPLTSRGSQQYRALTVPELTQQMFDAKNMMAACDPRHGRYLTVAAVFRGRMSMKEVDEQMLNVQNKNSSYFVEWIPNNVKTAVCDIPPRGLKMSATFIGNSTAIQELFKRISEQFTAMFRRKAFLHWYTGEGMDEMEFTEAESNMNDLVSEYQQYQDATADEQGEFEEEGEEDEA

Entity 3 Entity 3 polymer

Description description	Kinesin-like protein KIF2C
Molecular weight formula_weight	83721.8 kDa
Source method src_method	man
Copy count entity_count	1

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	M

MERLVATRLVTGLAVKIMRSNGVIHNANITSVNMDRSSVNVEWKEGEANKGKEISFADVISVNPELLDAVLAPTNVKENMPPQRNVSSQNHKRKTISKIPAPKEVAAKNSLLSESGAQSVLRERSTRMTAIHETLPYENEMEAESTPLPIQQNSVQARSRSTKVSIAEEPRLQTRISEIVEESLPSGRNNQGRRKSNIVKEMEKMKNKREEQRAQNYERRMKRAQDYDTSVPNWEFGKMIKEFRATMDCHRISMADPAEEHRICVCVRKRPLNKQELSKKEIDIISVPSKNIVLVHEPKLKVDLTKYLENQAFRFDFSFDETATNEVVYRFTARPLVQSIFEGGKATCFAYGQTGSGKTHTMGGDFSGKSQNVSKGVYAFASRDVFLLLDQPRYKHLDLDVFVTFFEIYNGKVFDLLNKKTKLRVLEDAKQEVQVVGLLEKQVISADDVFKMIEIGSACRTSGQTFANTSSSRSHACLQIILRRGSKLHGKFSLVDLAGNERGVDTASADRITRMEGAEINRSLLALKECIRALGQNKSHTPFRESKLTQILRDSFIGENSRTCMIAMLSPGFNSCEYTLNTLRYADRVKELSPQNAETNDDNLQMEDSGGSHASIEGLQLQDDFLLKDEELSTHNSFQDALNRVGELEDKAVDELRELVQKEPEWTNLLQMTEQPDYDLENFVMQAEYLIQERSKVLIALGDSINSLRLALQVEEQASKQISKKKRSNKSNSLEVLFQ

Source Source

Source organism organism	Xenopus laevis
Common name common_name	African clawed frog
NCBI taxonomy ID ncbi_taxonomy_id	8355
Host organism host_organism	Homo sapiens

Entity 4 Entity 4 non-polymer

Description description	GUANOSINE-5'-TRIPHOSPHATE
Molecular weight formula_weight	523.2 kDa
Source method src_method	syn
Copy count entity_count	4

Entity 5 Entity 5 non-polymer

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

Entity 6 Entity 6 non-polymer

Description description	GUANOSINE-5'-DIPHOSPHATE
Molecular weight formula_weight	443.2 kDa
Source method src_method	syn
Copy count entity_count	4

Entity 7 Entity 7 non-polymer

Description description	TAXOL
Molecular weight formula_weight	853.9 kDa
Source method src_method	syn
Copy count entity_count	4

▶

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	3.30 Å
Resolution测定Method resolution_method	—
颗粒数 num_particles	189746

Cryo-EM structure of the Xenopus laevis mitotic centromere-associated kinesin (MCAK) bound to the paclitaxel-stabilized microtubule

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

Tubulin alpha-1B chain

State in the Current Structure

Other States of the Same Protein in the Database

Tubulin beta chain

State in the Current Structure

Other States of the Same Protein in the Database

Kinesin-like protein KIF2C

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

9n9i__assembly_1__model_1

9n9i__assembly_1__model_1 | I(q)

9n9i__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 (7)

Entity 1 Entity 1 polymer

Polymer Polymer

Entity 2 Entity 2 polymer

Polymer Polymer

Entity 3 Entity 3 polymer

Polymer Polymer

Source Source

Entity 4 Entity 4 non-polymer

Entity 5 Entity 5 non-polymer

Entity 6 Entity 6 non-polymer

Entity 7 Entity 7 non-polymer

7. Citations (1)

Cryo-EM structure of the Xenopus laevis mitotic centromere-associated kinesin (MCAK) bound to the paclitaxel-stabilized microtubule

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

Tubulin alpha-1B 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

Tubulin beta 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

Kinesin-like protein KIF2C

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

9n9i__assembly_1__model_1

9n9i__assembly_1__model_1 | I(q)

9n9i__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 (7)

Entity 1 Entity 1 polymer

Polymer Polymer

Entity 2 Entity 2 polymer

Polymer Polymer

Entity 3 Entity 3 polymer

Polymer Polymer

Source Source

Entity 4 Entity 4 non-polymer

Entity 5 Entity 5 non-polymer

Entity 6 Entity 6 non-polymer

Entity 7 Entity 7 non-polymer

7. Citations (1)