1W0O

Vibrio cholerae sialidase


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.9 Å
  • R-Value Free: 0.218 
  • R-Value Work: 0.179 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Sialic Acid Recognition by Vibrio Cholerae Neuraminidase

Moustafa, I.Connaris, H.Taylor, M.Zaitsev, V.Wilsonm, J.C.Kiefel, J.Von-Itzstein, M.Taylor, G.

(2004) J.Biol.Chem. 279: 40819

  • DOI: 10.1074/jbc.M404965200
  • Primary Citation of Related Structures:  1W0P

  • PubMed Abstract: 
  • Vibrio cholerae neuraminidase (VCNA) plays a significant role in the pathogenesis of cholera by removing sialic acid from higher order gangliosides to unmask GM1, the receptor for cholera toxin. We previously showed that the structure of VCNA is comp ...

    Vibrio cholerae neuraminidase (VCNA) plays a significant role in the pathogenesis of cholera by removing sialic acid from higher order gangliosides to unmask GM1, the receptor for cholera toxin. We previously showed that the structure of VCNA is composed of a central beta-propeller catalytic domain flanked by two lectin-like domains; however the nature of the carbohydrates recognized by these lectin domains has remained unknown. We present here structures of the enzyme in complex with two substrates, alpha-2,3-sialyllactose and alpha-2,6-sialyllactose. Both substrate complexes reveal the alpha-anomer of N-acetylneuraminic acid (Neu5Ac) bound to the N-terminal lectin domain, thereby revealing the role of this domain. The large number of interactions suggest a relatively high binding affinity for sialic acid, which was confirmed by calorimetry, which gave a Kd approximately 30 microm. Saturation transfer difference NMR using a non-hydrolyzable substrate, Neu5,9Ac2-2-S-(alpha-2,6)-GlcNAcbeta1Me, was also used to map the ligand interactions at the VCNA lectin binding site. It is well known that VCNA can hydrolyze both alpha-2,3- and alpha-2,6-linked sialic acid substrates. In this study using alpha-2,3-sialyllactose co-crystallized with VCNA it was revealed that the inhibitor 2-deoxy-2,3-didehydro-N-acetylneuraminic acid (Neu5Ac2en) was bound at the catalytic site. This observation supports the notion that VCNA can produce its own inhibitor and has been further confirmed by 1H NMR analysis. The discovery of the sialic acid binding site in the N-lectin-like domain suggests that this might help target VCNA to sialic acid-rich environments, thereby enhancing the catalytic efficiency of the enzyme.


    Organizational Affiliation

    Centre for Biomolecular Sciences, University of St. Andrews, St. Andrews, Fife KY16 9ST, Scotland.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
SIALIDASE
A
781Vibrio cholerae serotype O1 (strain ATCC 39315 / El Tor Inaba N16961)Gene Names: nanH
EC: 3.2.1.18
Find proteins for P0C6E9 (Vibrio cholerae serotype O1 (strain ATCC 39315 / El Tor Inaba N16961))
Go to UniProtKB:  P0C6E9
Small Molecules
Ligands 3 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
CA
Query on CA

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

Download SDF File 
Download CCD File 
A
2-DEOXY-2,3-DEHYDRO-N-ACETYL-NEURAMINIC ACID
C11 H17 N O8
JINJZWSZQKHCIP-UFGQHTETSA-N
 Ligand Interaction
SIA
Query on SIA

Download SDF File 
Download CCD File 
A
O-SIALIC ACID
C11 H19 N O9
SQVRNKJHWKZAKO-YRMXFSIDSA-N
 Ligand Interaction
External Ligand Annotations 
IDBinding Affinity (Sequence Identity %)
DANIC50: 170000 nM (97) BINDINGDB
DANKd: ~37000 nM BINDINGMOAD
SIAKd: ~30000 nM BINDINGMOAD
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.9 Å
  • R-Value Free: 0.218 
  • R-Value Work: 0.179 
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 70.310α = 90.00
b = 74.910β = 90.00
c = 151.615γ = 90.00
Software Package:
Software NamePurpose
CNSrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2004-07-08
    Type: Initial release
  • Version 1.1: 2015-03-25
    Type: Database references, Derived calculations, Non-polymer description, Other, Version format compliance