Biological Assembly 1  

 3D View: Structure | 1D-3D View | Electron Density | Validation Report | Ligand Interaction

Global Symmetry: Dihedral - D3  (3D View)
Global Stoichiometry: Hetero 12-mer - A6B6 Pseudo Symmetry: Cyclic - C3  (3D View)
Pseudo Stoichiometry: Hetero 12-mer - A6B3C3 

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

Macromolecule Content

• Total Structure Weight: 12.08 kDa 
• Atom Count: 891 
• Modelled Residue Count: 104 
• Deposited Residue Count: 104 
• Unique protein chains: 2

2QIU

Structure of Human Arg-Insulin

• PDB DOI: 10.2210/pdb2QIU/pdb

• Classification: HORMONE
• Organism(s): Homo sapiens
• Mutation(s): No 


• Deposited: 2007-07-05 Released: 2008-02-26 
• Deposition Author(s): Sreekanth, R., Pattabhi, V., Rajan, S.S.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 2.00 Å
• R-Value Free: 0.249 
• R-Value Work: 0.197 
• R-Value Observed: 0.203 

Literature

Structural interpretation of reduced insulin activity as seen in the crystal structure of human Arg-insulin

Sreekanth, R., Pattabhi, V., Rajan, S.S.

(2008) Biochimie 90: 467-473

• PubMed: 18029081 
• DOI: 10.1016/j.biochi.2007.09.012
• Primary Citation of Related Structures:  
  2QIU


• PubMed Abstract: 
  

The N-terminal glycine of the A-chain in insulin is reported to be one of the residues that binds to the insulin receptor. Modifications near this region lead to variations in the biological activity of insulin. One such modification viz., an addition of an arginine at the N-terminal A-chain, was reported to possess two-thirds the activity of native insulin. The crystal structure of 2 zinc human arg (A0) insulin has been elucidated to 2A resolution to understand the mechanism of reduction in insulin activity. A conformational transition from T6 to T3R3(f) and a decrease in the surface accessibility of residues in the so called receptor binding region have been observed. The presence of arginine has also induced distortions in the A chain N-terminal helix. The subtle conformational alterations like decrease in surface accessibility, alterations in the charge surface and changes in the relative orientation of the two helices in the A chain may be responsible for the reduction in activity.

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Related Citations: 

• Structure of insulin in 4-zinc insulin
  Bentley, G., Dodson, E., Dodson, G., Hodgkin, D., Mercola, D.
  (1976) Nature 261: 166

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Organizational Affiliation: 

Centre of Advanced Study in Crystallography and Biophysics, University of Madras, Guindy Campus, Chennai, India.

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
Insulin	A, C	22	Homo sapiens	Mutation(s): 0  Gene Names: INS
UniProt & NIH Common Fund Data Resources
Find proteins for P01308 (Homo sapiens) Explore P01308  Go to UniProtKB:  P01308
PHAROS:  P01308

Entity ID: 2
Molecule	Chains	Sequence Length	Organism	Details	Image
Insulin	B, D	30	Homo sapiens	Mutation(s): 0  Gene Names: INS
UniProt & NIH Common Fund Data Resources
Find proteins for P01308 (Homo sapiens) Explore P01308  Go to UniProtKB:  P01308
PHAROS:  P01308

Small Molecules

Ligands 1 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
ZN	E [auth B], F [auth D]	ZINC ION Zn PTFCDOFLOPIGGS-UHFFFAOYSA-N

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 2.00 Å
• R-Value Free: 0.249 
• R-Value Work: 0.197 
• R-Value Observed: 0.203 
• Space Group: H 3

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 80.491	α = 90
b = 80.491	β = 90
c = 37.64	γ = 120

Software Package:

Software Name	Purpose
REFMAC	refinement
MAR345	data collection
AUTOMAR	data reduction
AMoRE	phasing

Structure Validation

Entry History 

Deposition Data

• Deposited Date: 2007-07-05 
• Released Date: 2008-02-26 
Deposition Author(s): Sreekanth, R., Pattabhi, V., Rajan, S.S.

Revision History  

• Version 1.0: 2008-02-26
  Type: Initial release
  
• Version 1.1: 2011-07-13
  Changes: Derived calculations, Version format compliance