4BUG

Pilus-presented adhesin, Spy0125 (Cpa), Cys426Ala mutant


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.8 Å
  • R-Value Free: 0.268 
  • R-Value Work: 0.211 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Intramolecular Isopeptide But not Internal Thioester Bonds Confer Proteolytic and Significant Thermal Stability to the S. Pyogenes Pilus Adhesin Spy0125.

Walden, M.Crow, A.Nelson, M.D.Banfield, M.J.

(2014) Proteins 82: 517

  • DOI: 10.1002/prot.24420

  • PubMed Abstract: 
  • Streptococcus pyogenes and other Gram-positive bacterial pathogens present long macromolecular filaments known as pili on their surface that mediate adhesion and colonization. These pili are covalent polymers, assembled by sortases. Typically, they c ...

    Streptococcus pyogenes and other Gram-positive bacterial pathogens present long macromolecular filaments known as pili on their surface that mediate adhesion and colonization. These pili are covalent polymers, assembled by sortases. Typically, they comprise a putative adhesin at their tip, a backbone subunit present in multiple copies and a basal subunit that is covalently anchored to the peptidoglycan layer of the cell surface. The crystal structures of pilin subunits revealed the presence of unusual covalent linkages in these proteins, including intramolecular isopeptide and internal thioester bonds. The intramolecular isopeptide bonds in backbone pilins are important for protein stability. Here, using both the wild-type protein and a set of mutants, we assessed the proteolytic and thermal stability of the S. pyogenes pilus tip adhesin Spy0125, in the presence and absence of its intramolecular isopeptide and internal thioester bonds. We also determined a crystal structure of the internal thioester bond variant Spy0125(Cys426Ala). We find that mutations in the intramolecular isopeptide bonds compromise the stability of Spy0125. Using limited proteolysis and thermal denaturation assays, we could separate the contribution of each intramolecular isopeptide bond to Spy0125 stability. In contrast, mutation in the internal thioester bond had a lesser effect on protein stability and the crystal structure is essentially identical to wild type. This work suggests that the internal thioester in Spy0125, although having a minor contributory role, is not required for protein stability and must have a different primary function, most likely mediating a covalent interaction with host cell ligands.


    Organizational Affiliation

    Department of Biological Chemistry, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, United Kingdom.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
ANCILLARY PROTEIN 1
A, B
457Streptococcus pyogenesMutation(s): 1 
Gene Names: cpa1
Find proteins for Q8GRA2 (Streptococcus pyogenes)
Go to UniProtKB:  Q8GRA2
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.8 Å
  • R-Value Free: 0.268 
  • R-Value Work: 0.211 
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 45.960α = 90.00
b = 116.860β = 90.00
c = 176.850γ = 90.00
Software Package:
Software NamePurpose
PHASERphasing
SCALAdata scaling
REFMACrefinement
MOSFLMdata reduction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2013-10-09
    Type: Initial release
  • Version 1.1: 2013-10-23
    Type: Database references
  • Version 1.2: 2014-02-19
    Type: Database references