Biological Assembly 1  

 3D View: Structure | Ligand Interaction

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Global Symmetry: Helical - H  (3D View)
Global Stoichiometry: Hetero 12-mer - A6B6 Pseudo Symmetry: Asymmetric - C1 
Pseudo Stoichiometry: Homo 12-mer -A12 

Biological assembly 1 assigned by authors and generated by PISA (software)

Macromolecule Content

• Total Structure Weight: 584962.94 
• Atom Count: 40470 
• Residue Count: 5178 
• Unique protein chains: 2

5N5N

Cryo-EM structure of tsA201 cell alpha1B and betaI and betaIVb microtubules

• DOI: 10.2210/pdb5N5N/pdb
• EMDataBank: EMD-3589

• Classification: STRUCTURAL PROTEIN
• Organism(s): Homo sapiens
• Expression System: Homo sapiens


• Deposited: 2017-02-14 Released: 2017-11-01 
• Deposition Author(s): Vemu, A., Atherton, J., Spector, J.O., Moores, C.A., Roll-Mecak, A.
• Funding Organization(s): Medical Research Council (United Kingdom); Intramural Programs of the NINDS and the NHLBI, National Institutes of Health 

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Experimental Data Snapshot

• Method: ELECTRON MICROSCOPY
• Resolution: 4.2 Å
• Aggregation State: FILAMENT 
• Reconstruction Method: SINGLE PARTICLE 

Literature

Tubulin isoform composition tunes microtubule dynamics.

Vemu, A., Atherton, J., Spector, J.O., Moores, C.A., Roll-Mecak, A.

(2017) Mol. Biol. Cell 28: 3564-3572

• PubMed: 29021343 
• DOI: 10.1091/mbc.E17-02-0124


• PubMed Abstract: 
  

Microtubules polymerize and depolymerize stochastically, a behavior essential for cell division, motility, and differentiation. While many studies advanced our understanding of how microtubule-associated proteins tune microtubule dynamics in trans, we have yet to understand how tubulin genetic diversity regulates microtubule functions. The majority of in vitro dynamics studies are performed with tubulin purified from brain tissue. This preparation is not representative of tubulin found in many cell types. Here we report the 4.2-Å cryo-electron microscopy (cryo-EM) structure and in vitro dynamics parameters of α1B/βI+βIVb microtubules assembled from tubulin purified from a human embryonic kidney cell line with isoform composition characteristic of fibroblasts and many immortalized cell lines. We find that these microtubules grow faster and transition to depolymerization less frequently compared with brain microtubules. Cryo-EM reveals that the dynamic ends of α1B/βI+βIVb microtubules are less tapered and that these tubulin heterodimers display lower curvatures. Interestingly, analysis of EB1 distributions at dynamic ends suggests no differences in GTP cap sizes. Last, we show that the addition of recombinant α1A/βIII tubulin, a neuronal isotype overexpressed in many tumors, proportionally tunes the dynamics of α1B/βI+βIVb microtubules. Our study is an important step toward understanding how tubulin isoform composition tunes microtubule dynamics.

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Organizational Affiliation: 

Cell Biology and Biophysics Unit, National Institute of Neurological Disorders and Stroke, Lung and Blood Institute, Bethesda, MD 20892.

Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details
Tubulin beta chain	B, A, C, D, E, F	426	Homo sapiens	Mutation(s): 0  Gene Names: TUBB (TUBB5)
Find proteins for P07437 (Homo sapiens) Go to Gene View: TUBB Go to UniProtKB:  P07437

Entity ID: 2
Molecule	Chains	Sequence Length	Organism	Details
Tubulin alpha-1B chain	K, G, H, I, J, L	437	Homo sapiens	Mutation(s): 0  Gene Names: TUBA1B
Find proteins for P68363 (Homo sapiens) Go to Gene View: TUBA1B Go to UniProtKB:  P68363

Small Molecules

Ligands 3 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram & Interactions
GTP	G, H, I, J, K, L	GUANOSINE-5'-TRIPHOSPHATE C10 H16 N5 O14 P3 XKMLYUALXHKNFT-UUOKFMHZSA-N
MG	A, B, C, D, E, F, G, H, I, J, K, L	MAGNESIUM ION Mg JLVVSXFLKOJNIY-UHFFFAOYSA-N
G2P	A, B, C, D, E, F	PHOSPHOMETHYLPHOSPHONIC ACID GUANYLATE ESTER C11 H18 N5 O13 P3 GXTIEXDFEKYVGY-KQYNXXCUSA-N

Experimental Data & Validation

Experimental Data

• Method: ELECTRON MICROSCOPY
• Resolution: 4.2 Å
• Aggregation State: FILAMENT 
• Reconstruction Method: SINGLE PARTICLE 

Software Package:

Software Name	Purpose
REFMAC	refinement

Structure Validation

Entry History & Funding Information

Deposition Data

• Deposited Date: 2017-02-14 
• Released Date: 2017-11-01 
• Deposition Author(s): Vemu, A., Atherton, J., Spector, J.O., Moores, C.A., Roll-Mecak, A.

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Funding Organization	Location	Grant Number
Medical Research Council (United Kingdom)	United Kingdom	--
Intramural Programs of the NINDS and the NHLBI, National Institutes of Health	United States	--

Revision History 

• Version 1.0: 2017-11-01
  Type: Initial release
• Version 1.1: 2017-12-13
  Type: Database references