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PDBsum entry 1b2g

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protein Protein-protein interface(s) links
Hormone/growth factor PDB id
1b2g
Jmol
Contents
Protein chains
21 a.a.
30 a.a. *
Waters ×49
* Residue conservation analysis
PDB id:
1b2g
Name: Hormone/growth factor
Title: Ph affects glu b13 switching and sulfate binding in cubic insulin crystals (ph 9.00 coordinates)
Structure: Protein (insulin a chain). Chain: a. Protein (insulin b chain). Chain: b
Source: Sus scrofa. Pig. Organism_taxid: 9823. Organ: pancreas. Organ: pancreas
Biol. unit: Dimer (from PQS)
Resolution:
1.80Å     R-factor:   0.200     R-free:   0.226
Authors: J.S.Diao,D.L.D.Caspar
Key ref:
J.Diao (2003). Crystallographic titration of cubic insulin crystals: pH affects GluB13 switching and sulfate binding. Acta Crystallogr D Biol Crystallogr, 59, 670-676. PubMed id: 12657786 DOI: 10.1107/S0907444903002208
Date:
26-Nov-98     Release date:   08-Apr-03    
PROCHECK
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 Headers
 References

Protein chain
Pfam   ArchSchema ?
P01315  (INS_PIG) -  Insulin
Seq:
Struc:
108 a.a.
21 a.a.
Protein chain
Pfam   ArchSchema ?
P01315  (INS_PIG) -  Insulin
Seq:
Struc:
108 a.a.
30 a.a.
Key:    PfamA domain  Secondary structure

 Gene Ontology (GO) functional annotation 
  GO annot!
  Cellular component     extracellular region   1 term 
  Biochemical function     hormone activity     1 term  

 

 
DOI no: 10.1107/S0907444903002208 Acta Crystallogr D Biol Crystallogr 59:670-676 (2003)
PubMed id: 12657786  
 
 
Crystallographic titration of cubic insulin crystals: pH affects GluB13 switching and sulfate binding.
J.Diao.
 
  ABSTRACT  
 
Structures of porcine insulin crystals soaked in 1 M sodium sulfate at pH 5.00, 5.53, 5.80, 6.00, 6.16, 6.26, 6.35, 6.50, 6.98 and 9.00 have been determined at between 1.7 and 1.9 A resolution. GluB13 exhibits a single conformation at pH </= 5.80, two conformations between pH 6.00 and 6.98 and a single conformation at pH 9.00. Between pH 6.00 and 6.98, the conformation of GluB13 switches from one rotamer to another rotamer. Between pH 6.16 and 6.26, PheB1 undergoes a significant conformational change. By pH 9.00 many residues have undergone relatively large shifts and HisB10 exhibits a double conformation. As a result of the pH increase, the occupancy of the sulfate ion decreases from a maximum of 1.00 at pH 5.00 to a minimum of 0.46 at pH 6.50. Comparison of the structures, the observed and calculated structure factors and map correlation coefficients indicate that the porcine insulin structure changes gradually as a function of pH.
 
  Selected figure(s)  
 
Figure 2.
Figure 2 Structures at ten different pH and corresponding 2F[o] - F[c] maps. Structures in the region of GluB13 and the sulfate ion are presented and 2F[o] - F[c] maps are contoured at the 0.8 level because of the approximate half-occupancy of the two rotamers of GluB13 and the lower electron density compared with the rest of the structure. Sub-figures correspond to the structures at pH 5.00, 5.53, 5.80, 6.00, 6.16, 6.26, 6.35, 6.50, 6.98 and 9.00, respectively.
Figure 4.
Figure 4 Sulfate-binding region. The coordinates at pH 5.00 were used to produce the figure.
 
  The above figures are reprinted by permission from the IUCr: Acta Crystallogr D Biol Crystallogr (2003, 59, 670-676) copyright 2003.  
  Figures were selected by an automated process.  

Literature references that cite this PDB file's key reference

  PubMed id Reference
18156668 N.Niimura, and R.Bau (2008).
Neutron protein crystallography: beyond the folding structure of biological macromolecules.
  Acta Crystallogr A, 64, 12-22.  
17899393 L.Wang, H.R.Eghbalnia, and J.L.Markley (2007).
Nearest-neighbor effects on backbone alpha and beta carbon chemical shifts in proteins.
  J Biomol NMR, 39, 247-257.  
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