Macromolecule Content

• Total Structure Weight: 35.47 kDa 
• Atom Count: 2472 
• Residue Count: 306 
• Unique protein chains: 2

3AIY

R6 HUMAN INSULIN HEXAMER (SYMMETRIC), NMR, REFINED AVERAGE STRUCTURE

• DOI: 10.2210/pdb3AIY/pdb

• Classification: HORMONE/GROWTH FACTOR
• Mutation(s): No 


• Deposited: 1998-12-29 Released: 2000-02-28 
• Deposition Author(s): O'Donoghue, S.I., Chang, X., Abseher, R., Nilges, M., Led, J.J.

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Experimental Data Snapshot

• Method: SOLUTION NMR
• Conformers Calculated: 40 
• Conformers Submitted: 1 
• Selection Criteria: LOWEST TOTAL ENERGY 

Literature

Unraveling the symmetry ambiguity in a hexamer: calculation of the R6 human insulin structure.

O'Donoghue, S.I., Chang, X., Abseher, R., Nilges, M., Led, J.J.

(2000) J Biomol NMR 16: 93-108

• PubMed: 10723989 
• DOI: 10.1023/a:1008323819099
• Primary Citation of Related Structures:  
  5AIY, 3AIY, 4AIY, 2AIY


• PubMed Abstract: 
  

Crystallographic and NMR studies of insulin have revealed a highly flexible molecule with a range of different aggregation and structural states; the importance of these states for the function of the hormone is still unclear. To address this question, we have studied the solution structure of the insulin R6 symmetric hexamer using NMR spectroscopy. Structure determination of symmetric oligomers by NMR is complicated due to 'symmetry ambiguity' between intra- and intermonomer NOEs, and between different classes of intermonomer NOEs. Hence, to date, only two symmetric tetramers and one symmetric pentamer (VTB, B subunit of verotoxin) have been solved by NMR: there has been no other symmetric hexamer or higher-order oligomer. Recently, we reported a solution structure for R6 insulin hexamer. However, in that study, a crystal structure was used as a reference to resolve ambiguities caused by the threefold symmetry; the same method was used in solving VTB. Here, we have successfully recalculated R6 insulin using the symmetry-ADR method, a computational strategy in which ambiguities are resolved using the NMR data alone. Thus the obtained structure is a refinement of the previous R6 solution structure. Correlated motions in the final structural ensemble were analysed using a recently developed principal component method; this suggests the presence of two major conformational substates. The study demonstrates that the solution structure of higher-order symmetric oligomers can be determined unambiguously from NMR data alone, using the symmetry-ADR method. This success bodes well for future NMR studies of higher-order symmetric oligomers. The correlated motions observed in the structural ensemble suggest a new insight into the mechanism of phenol exchange and the T6 <--> R6 transition of insulin in solution.

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Related Citations: 

• Calculation of Symmetric Oligomer Structures from NMR Data
  O'Donoghue, S.I., Nilges, M.
  (1999) Structure, Computation And Dynamics In Protein Nmr (in: Biological Magnetic Resonance, V 17) --: --

• Solution Structures of the R6 Human Insulin Hexamer
  Chang, X., Jorgensen, A.M., Bardrum, P., Led, J.J.
  (1997) Biochemistry 36: 9409

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Organizational Affiliation: 

European Molecular Biology Laboratory, Heidelberg, Germany.

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
PROTEIN (INSULIN)	A, C, E, G, I, K	21	N/A	Mutation(s): 0
Find proteins for P01308 (Homo sapiens) Explore P01308  Go to UniProtKB:  P01308
NIH Common Fund Data Resources
PHAROS  P01308

Entity ID: 2
Molecule	Chains	Sequence Length	Organism	Details	Image
PROTEIN (INSULIN)	B, D, F, H, J, L	30	N/A	Mutation(s): 0
Find proteins for P01308 (Homo sapiens) Explore P01308  Go to UniProtKB:  P01308
NIH Common Fund Data Resources
PHAROS  P01308

Small Molecules

Ligands 1 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
IPH	A, C, E, G, I, K	PHENOL C6 H6 O ISWSIDIOOBJBQZ-UHFFFAOYSA-N

Experimental Data & Validation

Experimental Data

• Method: SOLUTION NMR
• Conformers Calculated: 40 
• Conformers Submitted: 1 
• Selection Criteria: LOWEST TOTAL ENERGY 
• OLDERADO: 3AIY Olderado

Structure Validation

Entry History 

Deposition Data

• Deposited Date: 1998-12-29 
• Released Date: 2000-02-28 
Deposition Author(s): O'Donoghue, S.I., Chang, X., Abseher, R., Nilges, M., Led, J.J.

Revision History 

• Version 1.0: 2000-02-28
  Type: Initial release
  
• Version 1.1: 2008-04-27
  Changes: Version format compliance
• Version 1.2: 2011-07-13
  Changes: Version format compliance