3BXQ

The structure of a mutant insulin uncouples receptor binding from protein allostery. An electrostatic block to the TR transition


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.30 Å
  • R-Value Free: 0.232 
  • R-Value Work: 0.206 

wwPDB Validation   3D Report Full Report


This is version 1.3 of the entry. See complete history


Literature

The structure of a mutant insulin uncouples receptor binding from protein allostery. An electrostatic block to the TR transition.

Wan, Z.L.Huang, K.Hu, S.Q.Whittaker, J.Weiss, M.A.

(2008) J Biol Chem 283: 21198-21210

  • DOI: 10.1074/jbc.M800235200
  • Primary Citation of Related Structures:  
    3BXQ

  • PubMed Abstract: 
  • The zinc insulin hexamer undergoes allosteric reorganization among three conformational states, designated T(6), T(3)R(3)(f), and R(6). Although the free monomer in solution (the active species) resembles the classical T-state, an R-like conformational change is proposed to occur upon receptor binding ...

    The zinc insulin hexamer undergoes allosteric reorganization among three conformational states, designated T(6), T(3)R(3)(f), and R(6). Although the free monomer in solution (the active species) resembles the classical T-state, an R-like conformational change is proposed to occur upon receptor binding. Here, we distinguish between the conformational requirements of receptor binding and the crystallographic TR transition by design of an active variant refractory to such reorganization. Our strategy exploits the contrasting environments of His(B5) in wild-type structures: on the T(6) surface but within an intersubunit crevice in R-containing hexamers. The TR transition is associated with a marked reduction in His(B5) pK(a), in turn predicting that a positive charge at this site would destabilize the R-specific crevice. Remarkably, substitution of His(B5) (conserved among eutherian mammals) by Arg (occasionally observed among other vertebrates) blocks the TR transition, as probed in solution by optical spectroscopy. Similarly, crystallization of Arg(B5)-insulin in the presence of phenol (ordinarily a potent inducer of the TR transition) yields T(6) hexamers rather than R(6) as obtained in control studies of wild-type insulin. The variant structure, determined at a resolution of 1.3A, closely resembles the wild-type T(6) hexamer. Whereas Arg(B5) is exposed on the protein surface, its side chain participates in a solvent-stabilized network of contacts similar to those involving His(B5) in wild-type T-states. The substantial receptor-binding activity of Arg(B5)-insulin (40% relative to wild type) demonstrates that the function of an insulin monomer can be uncoupled from its allosteric reorganization within zinc-stabilized hexamers.


    Related Citations: 
    • Design of an active ultrastable single-chain insulin analog: synthesis, structure, and therapeutic implications.
      Hua, Q.X., Nakagawa, S.H., Jia, W., Huang, K., Phillips, N.B., Hu, S.Q., Weiss, M.A.
      (2008) J Biol Chem 283: 14703
    • The structure of 2zn pig insulin crystal at 1.5 A resolution
      Baker, E.N., Blujdell, T.L., Cutfield, J.F., Cutfield, S.M., Dodson, E.J., Dodson, G.G., Hodgkin, D., Isaacs, N.W., Reynolds, C.D.
      (1988) Philos Trans R Soc London,ser B 319: 369
    • Structure of insulin in 4-zinc insulin
      Bentley, G., Dodson, E., Dodson, G., Hodgkin, D., Mercola, D.
      (1976) Nature 261: 166
    • Phenol stabilizes more helix in a new symmetrical zinc insulin hexamer
      Derewenda, U., Derewenda, Z., Dodson, E., Dodson, G., Reynold, C., Smith, G., Sparks, C., Swenson, D.
      (1989) Nature 338: 594
    • Toward the active conformation of insulin: stereospecific modulation of a structural swith in the B chain
      Hua, Q.X., Nakagawa, S., Hu, S.Q., Jia, W., Wang, S., Weiss, M.A.
      (2006) J Biol Chem 281: 24900

    Organizational Affiliation

    Departments of Biochemistry and Nutrition, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
insulin A chainA, C21N/AMutation(s): 0 
UniProt & NIH Common Fund Data Resources
Find proteins for P01308 (Homo sapiens)
Explore P01308 
Go to UniProtKB:  P01308
PHAROS:  P01308
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP01308
Protein Feature View
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  • Reference Sequence
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetailsImage
insulin B chainB, D30N/AMutation(s): 1 
UniProt & NIH Common Fund Data Resources
Find proteins for P01308 (Homo sapiens)
Explore P01308 
Go to UniProtKB:  P01308
PHAROS:  P01308
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP01308
Protein Feature View
Expand
  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
ZN
Query on ZN

Download Ideal Coordinates CCD File 
E [auth B],
F [auth D]
ZINC ION
Zn
PTFCDOFLOPIGGS-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.30 Å
  • R-Value Free: 0.232 
  • R-Value Work: 0.206 
  • Space Group: H 3
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 81.39α = 90
b = 81.39β = 90
c = 34γ = 120
Software Package:
Software NamePurpose
HKL-2000data collection
CNSrefinement
d*TREKdata reduction
d*TREKdata scaling
CNSphasing

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2008-05-20
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Version format compliance
  • Version 1.2: 2021-10-20
    Changes: Database references, Derived calculations
  • Version 1.3: 2022-04-13
    Changes: Database references