Macromolecule Content

• Total Structure Weight: 25.21 kDa 
• Atom Count: 1776 
• Modelled Residue Count: 224 
• Deposited Residue Count: 224 
• Unique protein chains: 1

1MPE

Ensemble of 20 structures of the tetrameric mutant of the B1 domain of streptococcal protein G

• DOI: 10.2210/pdb1MPE/pdb
• BMRB: 5654

• Classification: PROTEIN BINDING
• Organism(s): Streptococcus sp. 'group G
• Expression System: Escherichia coli
• Mutation(s): Yes 


• Deposited: 2002-09-12 Released: 2002-10-30 
• Deposition Author(s): Frank, M.K., Dyda, F., Dobrodumov, A., Gronenborn, A.M.

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Experimental Data Snapshot

• Method: SOLUTION NMR
• Conformers Calculated: 100 
• Conformers Submitted: 21 
• Selection Criteria: structures with least restraint violations and phi, psi angles of residue 46 in allowed region of Ramachrandran plot 

Literature

Core mutations switch monomeric protein GB1 into an intertwined tetramer.

Kirsten Frank, M., Dyda, F., Dobrodumov, A., Gronenborn, A.M.

(2002) Nat Struct Biol 9: 877-885

• PubMed: 12379842 
• DOI: 10.1038/nsb854
• Primary Citation of Related Structures:  
  1MPE, 1MVK


• PubMed Abstract: 
  

The structure of a mutant immunoglobulin-binding B1 domain of streptococcal protein G (GB1), which comprises five conservative changes in hydrophobic core residues, was determined by NMR spectroscopy and X-ray crystallography. The oligomeric state and quaternary structure of the mutant protein are drastically changed from the wild type protein. The mutant structure consists of a symmetric tetramer, with intermolecular strand exchange involving all four units. Four of the five secondary structure elements present in the monomeric wild type GB1 structure are retained in the tetrameric structure, although their intra- and intermolecular interactions are altered. Our results demonstrate that through the acquisition of a moderate number of pivotal point mutations, proteins such as GB1 are able to undergo drastic structural changes, overcoming reduced stability of the monomeric unit by multimerization. The present structure is an illustrative example of how proteins exploit the breadth of conformational space.

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Related Citations: 

• A Novel, Highly Stable Fold of the Immunoglobulin Binding Domain of Streptococcal Protein G.
  Gronenborn, A.M., Filpula, D.R., Essig, N.Z., Achari, A., Whitlow, M., Wingfield, P.T., Clore, G.M.
  (1991) Science 253: 657

• Core Mutants of the Immunoglobulin Binding Domain of Streptococcal Protein G: Stability and Structural Integrity
  Gronenborn, A.M., Frank, M.K., Clore, G.M.
  (1996) FEBS Lett 398: 312

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Organizational Affiliation: 

Laboratories of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA.

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
Immunoglobulin G binding protein G	A, B, C, D	56	Streptococcus sp. 'group G	Mutation(s): 6  Gene Names: spg
Find proteins for P06654 (Streptococcus sp. group G) Explore P06654  Go to UniProtKB:  P06654

Experimental Data & Validation

Experimental Data

• Method: SOLUTION NMR
• Conformers Calculated: 100 
• Conformers Submitted: 21 
• Selection Criteria: structures with least restraint violations and phi, psi angles of residue 46 in allowed region of Ramachrandran plot 
• OLDERADO: 1MPE Olderado

Structure Validation

Entry History 

Deposition Data

• Deposited Date: 2002-09-12 
• Released Date: 2002-10-30 
Deposition Author(s): Frank, M.K., Dyda, F., Dobrodumov, A., Gronenborn, A.M.

Revision History  

• Version 1.0: 2002-10-30
  Type: Initial release
  
• Version 1.1: 2008-04-28
  Changes: Version format compliance
• Version 1.2: 2011-07-13
  Changes: Version format compliance