4YZ4

Crystal Structure of Streptococcus pneumoniae NanC, in complex with N-Acetylneuraminic acid.


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.15 Å
  • R-Value Free: 0.239 
  • R-Value Work: 0.203 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Streptococcus pneumoniae NanC: STRUCTURAL INSIGHTS INTO THE SPECIFICITY AND MECHANISM OF A SIALIDASE THAT PRODUCES A SIALIDASE INHIBITOR.

Owen, C.D.Lukacik, P.Potter, J.A.Sleator, O.Taylor, G.L.Walsh, M.A.

(2015) J.Biol.Chem. 290: 27736-27748

  • DOI: 10.1074/jbc.M115.673632
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • Streptococcus pneumoniae is an important human pathogen that causes a range of disease states. Sialidases are important bacterial virulence factors. There are three pneumococcal sialidases: NanA, NanB, and NanC. NanC is an unusual sialidase in that i ...

    Streptococcus pneumoniae is an important human pathogen that causes a range of disease states. Sialidases are important bacterial virulence factors. There are three pneumococcal sialidases: NanA, NanB, and NanC. NanC is an unusual sialidase in that its primary reaction product is 2-deoxy-2,3-didehydro-N-acetylneuraminic acid (Neu5Ac2en, also known as DANA), a nonspecific hydrolytic sialidase inhibitor. The production of Neu5Ac2en from α2-3-linked sialosides by the catalytic domain is confirmed within a crystal structure. A covalent complex with 3-fluoro-β-N-acetylneuraminic acid is also presented, suggesting a common mechanism with other sialidases up to the final step of product formation. A conformation change in an active site hydrophobic loop on ligand binding constricts the entrance to the active site. In addition, the distance between the catalytic acid/base (Asp-315) and the ligand anomeric carbon is unusually short. These features facilitate a novel sialidase reaction in which the final step of product formation is direct abstraction of the C3 proton by the active site aspartic acid, forming Neu5Ac2en. NanC also possesses a carbohydrate-binding module, which is shown to bind α2-3- and α2-6-linked sialosides, as well as N-acetylneuraminic acid, which is captured in the crystal structure following hydration of Neu5Ac2en by NanC. Overall, the pneumococcal sialidases show remarkable mechanistic diversity while maintaining a common structural scaffold.


    Organizational Affiliation

    From the Biomedical Sciences Research Complex, University of St. Andrews, St. Andrews, Fife KY16 9ST, United Kingdom.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Sialidase, NanC
A, B
677Streptococcus pneumoniae serotype 4 (strain ATCC BAA-334 / TIGR4)Mutation(s): 0 
EC: 3.2.1.18
Find proteins for A0A0H2UQE4 (Streptococcus pneumoniae serotype 4 (strain ATCC BAA-334 / TIGR4))
Go to UniProtKB:  A0A0H2UQE4
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
SO4
Query on SO4

Download SDF File 
Download CCD File 
A, B
SULFATE ION
O4 S
QAOWNCQODCNURD-UHFFFAOYSA-L
 Ligand Interaction
SIA
Query on SIA

Download SDF File 
Download CCD File 
A, B
O-SIALIC ACID
C11 H19 N O9
SQVRNKJHWKZAKO-YRMXFSIDSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.15 Å
  • R-Value Free: 0.239 
  • R-Value Work: 0.203 
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 73.380α = 90.00
b = 136.090β = 90.00
c = 150.440γ = 90.00
Software Package:
Software NamePurpose
xia2data scaling
PDB_EXTRACTdata extraction
xia2data reduction
REFMACrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
Medical Research Council (United Kingdom)United Kingdom--

Revision History 

  • Version 1.0: 2015-09-23
    Type: Initial release
  • Version 1.1: 2015-11-25
    Type: Database references
  • Version 1.2: 2017-09-13
    Type: Author supporting evidence