Biological Assembly 1  

 3D View: Structure | Electron Density | Ligand Interaction

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Global Symmetry: Cyclic - C3  (3D View)
Global Stoichiometry: Homo 3-mer - A3 

Biological assembly 1 generated by PISA (software)

Macromolecule Content

• Total Structure Weight: 148713.89 
• Atom Count: 9331 
• Residue Count: 1347 
• Unique protein chains: 1

3IO4

Huntingtin amino-terminal region with 17 Gln residues - Crystal C90

• DOI: 10.2210/pdb3IO4/pdb

• Classification: SIGNALING PROTEIN
• Organism(s): Escherichia coli O157:H7, Homo sapiens
• Expression System: Escherichia coli


• Deposited: 2009-08-13 Released: 2009-10-27 
• Deposition Author(s): Kim, M.W., Chelliah, Y., Kim, S.W., Otwinowski, Z., Bezprozvanny, I.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 3.63 Å
• R-Value Free: 0.304 
• R-Value Work: 0.251 

Literature

Secondary structure of Huntingtin amino-terminal region.

Kim, M.W., Chelliah, Y., Kim, S.W., Otwinowski, Z., Bezprozvanny, I.

(2009) Structure 17: 1205-1212

• PubMed: 19748341 
• DOI: 10.1016/j.str.2009.08.002
• Primary Citation of Related Structures:  
  3IOW, 3IOV, 3IOU, 3IOT, 3IOR, 3IO6


• PubMed Abstract: 
  

Huntington's disease is a genetic neurodegenerative disorder resulting from polyglutamine (polyQ) expansion (>36Q) within the first exon of Huntingtin (Htt) protein. We applied X-ray crystallography to determine the secondary structure of the first exon (EX1) of Htt17Q. The structure of Htt17Q-EX1 consists of an amino-terminal alpha helix, poly17Q region, and polyproline helix formed by the proline-rich region. The poly17Q region adopts multiple conformations in the structure, including alpha helix, random coil, and extended loop. The conformation of the poly17Q region is influenced by the conformation of neighboring protein regions, demonstrating the importance of the native protein context. We propose that the conformational flexibility of the polyQ region observed in our structure is a common characteristic of many amyloidogenic proteins. We further propose that the pathogenic polyQ expansion in the Htt protein increases the length of the random coil, which promotes aggregation and facilitates abnormal interactions with other proteins in cells.

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Organizational Affiliation: 

Department of Biochemistry, University of Texas Southwestern Medical Center at Dallas, Dallas, TX 75390, USA. [e-mail]

Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details
Maltose-binding periplasmic protein,Huntingtin fusion protein	A, B, C	449	Escherichia coli O157:H7, Homo sapiens This entity is chimeric	Mutation(s): 0  Gene Names: malE, HTT (HD, IT15)
Find proteins for P0AEY0 (Escherichia coli O157:H7) Go to UniProtKB:  P0AEY0
Find proteins for P42858 (Homo sapiens) Go to Gene View: HTT Go to UniProtKB:  P42858

Small Molecules

Ligands 2 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram & Interactions
ZN	A, B, C	ZINC ION Zn PTFCDOFLOPIGGS-UHFFFAOYSA-N
CA	B, C	CALCIUM ION Ca BHPQYMZQTOCNFJ-UHFFFAOYSA-N

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 3.63 Å
• R-Value Free: 0.304 
• R-Value Work: 0.251 
• Space Group: C 1 2 1

Unit Cell:

Length (Å)	Angle (°)
a = 162.950	α = 90.00
b = 101.210	β = 90.42
c = 142.050	γ = 90.00

Software Package:

Software Name	Purpose
REFMAC	refinement
HKL-2000	data reduction
HKL-2000	data collection
PHASES	phasing
HKL-2000	data scaling

Structure Validation

Entry History 

Deposition Data

• Deposited Date: 2009-08-13 
• Released Date: 2009-10-27 
• Deposition Author(s): Kim, M.W., Chelliah, Y., Kim, S.W., Otwinowski, Z., Bezprozvanny, I.

Revision History 

• Version 1.0: 2009-10-27
  Type: Initial release
• Version 1.1: 2011-07-13
  Type: Version format compliance
• Version 2.0: 2017-06-21
  Type: Advisory, Atomic model, Database references, Derived calculations, Source and taxonomy, Structure summary