1EM7

HELIX VARIANT OF THE B1 DOMAIN FROM STREPTOCOCCAL PROTEIN G

• PDB DOI: https://doi.org/10.2210/pdb1EM7/pdb

• Classification: MEMBRANE PROTEIN
• Organism(s): Streptococcus sp.
• Expression System: Escherichia coli BL21(DE3)
• Mutation(s): Yes 


• Deposited: 2000-03-16 Released: 2002-05-08 
• Deposition Author(s): Strop, P., Marinescu, A.M., Mayo, S.L.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 2.00 Å
• R-Value Free: 0.267 
• R-Value Work: 0.235 

Literature

Structure of a protein G helix variant suggests the importance of helix propensity and helix dipole interactions in protein design.

Strop, P., Marinescu, A.M., Mayo, S.L.

(2000) Protein Sci 9: 1391-1394

• PubMed: 10933505 
• DOI: https://doi.org/10.1110/ps.9.7.1391
• Primary Citation of Related Structures:  
  1EM7


• PubMed Abstract: 
  

  Six helix surface positions of protein G (Gbeta1) were redesigned using a computational protein design algorithm, resulting in the five fold mutant Gbeta1m2. Gbeta1m2 is well folded with a circular dichroism spectrum nearly identical to that of Gbeta1, and a melting temperature of 91 degrees C, approximately 6 degrees C higher than that of Gbeta1. The crystal structure of Gbeta1m2 was solved to 2.0 A resolution by molecular replacement. The absence of hydrogen bond or salt bridge interactions between the designed residues in Gbeta1m2 suggests that the increased stability of Gbeta1m2 is due to increased helix propensity and more favorable helix dipole interactions.

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Organizational Affiliation: 

Biochemistry Option, California Institute of Technology, Pasadena, California 91125, USA.

Biological Assembly 1  

Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Monomer - A1 

Biological assembly 1 assigned by authors.

Macromolecule Content

• Total Structure Weight: 6.29 kDa 
• Atom Count: 472 
• Modelled Residue Count: 56 
• Deposited Residue Count: 56 
• Unique protein chains: 1

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
PROTEIN G	A	56	Streptococcus sp.	Mutation(s): 4
UniProt
Find proteins for P06654 (Streptococcus sp. group G) Explore P06654  Go to UniProtKB:  P06654

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 2.00 Å
• R-Value Free: 0.267 
• R-Value Work: 0.235 
• Space Group: P 4 2₁ 2

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 52.61	α = 90
b = 52.61	β = 90
c = 44.59	γ = 90

Software Package:

Software Name	Purpose
AMoRE	phasing
CNS	refinement
MAR345	data collection
SCALEPACK	data scaling

Structure Validation

Entry History 

Deposition Data

• Released Date: 2002-05-08 
Deposition Author(s): Strop, P., Marinescu, A.M., Mayo, S.L.

Revision History  

• Version 1.0: 2002-05-08
  Type: Initial release
  
• Version 1.1: 2008-04-27
  Changes: Version format compliance
• Version 1.2: 2011-07-13
  Changes: Version format compliance
• Version 1.3: 2017-10-04
  Changes: Advisory, Refinement description
• Version 1.4: 2021-11-03
  Changes: Advisory, Database references
• Version 1.5: 2024-02-07
  Changes: Data collection