4CUB

Unravelling the multiple functions of the architecturally intricate Streptococcus pneumoniae beta-galactosidase, BgaA


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.1 Å
  • R-Value Free: 0.247 
  • R-Value Work: 0.190 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Unravelling the Multiple Functions of the Architecturally Intricate Streptococcus Pneumoniae Beta-Galactosidase, Bgaa.

Singh, A.K.Pluvinage, B.Higgins, M.A.Dalia, A.B.Woodiga, S.A.Flynn, M.Lloyd, A.R.Weiser, J.N.Stubbs, K.A.Boraston, A.B.King, S.J.

(2014) Plos Pathog. 10: 04364

  • DOI: 10.1371/journal.ppat.1004364
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • Bacterial cell-surface proteins play integral roles in host-pathogen interactions. These proteins are often architecturally and functionally sophisticated and yet few studies of such proteins involved in host-pathogen interactions have defined the do ...

    Bacterial cell-surface proteins play integral roles in host-pathogen interactions. These proteins are often architecturally and functionally sophisticated and yet few studies of such proteins involved in host-pathogen interactions have defined the domains or modules required for specific functions. Streptococcus pneumoniae (pneumococcus), an opportunistic pathogen that is a leading cause of community acquired pneumonia, otitis media and bacteremia, is decorated with many complex surface proteins. These include β-galactosidase BgaA, which is specific for terminal galactose residues β-1-4 linked to glucose or N-acetylglucosamine and known to play a role in pneumococcal growth, resistance to opsonophagocytic killing, and adherence. This study defines the domains and modules of BgaA that are required for these distinct contributions to pneumococcal pathogenesis. Inhibitors of β-galactosidase activity reduced pneumococcal growth and increased opsonophagocytic killing in a BgaA dependent manner, indicating these functions require BgaA enzymatic activity. In contrast, inhibitors increased pneumococcal adherence suggesting that BgaA bound a substrate of the enzyme through a distinct module or domain. Extensive biochemical, structural and cell based studies revealed two newly identified non-enzymatic carbohydrate-binding modules (CBMs) mediate adherence to the host cell surface displayed lactose or N-acetyllactosamine. This finding is important to pneumococcal biology as it is the first adhesin-carbohydrate receptor pair identified, supporting the widely held belief that initial pneumococcal attachment is to a glycoconjugate. Perhaps more importantly, this is the first demonstration that a CBM within a carbohydrate-active enzyme can mediate adherence to host cells and thus this study identifies a new class of carbohydrate-binding adhesins and extends the paradigm of CBM function. As other bacterial species express surface-associated carbohydrate-active enzymes containing CBMs these findings have broad implications for bacterial adherence. Together, these data illustrate that comprehending the architectural sophistication of surface-attached proteins can increase our understanding of the different mechanisms by which these proteins can contribute to bacterial pathogenesis.


    Organizational Affiliation

    Center for Microbial Pathogenesis, The Research Institute at Nationwide Children's Hospital, Columbus, Ohio, United States of America.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
BETA-GALACTOSIDASE
A, B
183Streptococcus pneumoniae (strain ATCC BAA-255 / R6)Mutation(s): 0 
Gene Names: bgaA
EC: 3.2.1.23
Find proteins for Q8DQP4 (Streptococcus pneumoniae (strain ATCC BAA-255 / R6))
Go to UniProtKB:  Q8DQP4
Small Molecules
Ligands 4 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
CA
Query on CA

Download SDF File 
Download CCD File 
A, B
CALCIUM ION
Ca
BHPQYMZQTOCNFJ-UHFFFAOYSA-N
 Ligand Interaction
GAL
Query on GAL

Download SDF File 
Download CCD File 
A, B
BETA-D-GALACTOSE
C6 H12 O6
WQZGKKKJIJFFOK-FPRJBGLDSA-N
 Ligand Interaction
EDO
Query on EDO

Download SDF File 
Download CCD File 
A, B
1,2-ETHANEDIOL
ETHYLENE GLYCOL
C2 H6 O2
LYCAIKOWRPUZTN-UHFFFAOYSA-N
 Ligand Interaction
NAG
Query on NAG

Download SDF File 
Download CCD File 
A, B
N-ACETYL-D-GLUCOSAMINE
C8 H15 N O6
OVRNDRQMDRJTHS-FMDGEEDCSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.1 Å
  • R-Value Free: 0.247 
  • R-Value Work: 0.190 
  • Space Group: P 43 21 2
Unit Cell:
Length (Å)Angle (°)
a = 70.530α = 90.00
b = 70.530β = 90.00
c = 161.560γ = 90.00
Software Package:
Software NamePurpose
PHASERphasing
MOSFLMdata reduction
REFMACrefinement
SCALAdata scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2014-08-20
    Type: Initial release
  • Version 1.1: 2014-09-24
    Type: Database references
  • Version 1.2: 2017-04-19
    Type: Data collection