2XQV

The X-ray structure of the Zn(II) bound ZnuA from Salmonella enterica


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.93 Å
  • R-Value Free: 0.228 
  • R-Value Work: 0.206 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

The X-Ray Structure of the Zinc Transporter Znua from Salmonella Enterica Discloses a Unique Triad of Zinc Coordinating Histidines.

Ilari, A.Alaleona, F.Petrarca, P.Battistoni, A.Chiancone, E.

(2011) J.Mol.Biol. 409: 630

  • DOI: 10.1016/j.jmb.2011.04.036
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • ZnuA is the soluble component of the high-affinity ZnuABC zinc transporter belonging to the cluster 9 group of ATP-binding cassette-type periplasmic Zn- and Mn-binding proteins. In Gram-negative bacteria, the ZnuABC system is essential for zinc uptak ...

    ZnuA is the soluble component of the high-affinity ZnuABC zinc transporter belonging to the cluster 9 group of ATP-binding cassette-type periplasmic Zn- and Mn-binding proteins. In Gram-negative bacteria, the ZnuABC system is essential for zinc uptake and homeostasis and is an important determinant of bacterial resistance to the host defense mechanisms. The cluster 9 members share a two (α/β)(4) domain architecture with a long α-helix connecting the two domains. In the Zn-specific proteins, the so-called α3c and the α4 helices are separated by an insert of variable length, rich in histidine and negatively charged residues. This distinctive His-rich loop is proposed to play a role in the management of zinc also due to its location at the entrance of the metal binding site located at the domain interface. The known Synechocystis 6803 and Escherichia coli ZnuA structures show the same metal coordination involving three conserved histidines and a glutamic acid or a water molecule as fourth ligand. The structures of Salmonella enterica ZnuA, with a partially or fully occupied zinc binding site, and of a deletion mutant missing a large part of the His-rich loop revealed unexpected differences in the metal-coordinating ligands, as histidine 140 from the mobile (at the C-terminal) part of the loop substitutes the conserved histidine 60. This unforeseen coordination is rendered possible by the "open conformation" of the two domains. The possible structural determinants of these peculiarities and their functional relevance are discussed.


    Organizational Affiliation

    CNR Institute of Molecular Biology and Pathology and Department of Biochemical Sciences, Sapienza University of Rome, Piazzale Aldo Moro 5, 00185 Rome, Italy.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
ZINC ABC TRANSPORTER, PERIPLASMIC ZINC-BINDING PROTEIN
A
288Salmonella typhimurium (strain LT2 / SGSC1412 / ATCC 700720)Mutation(s): 0 
Gene Names: znuA
Find proteins for Q8ZNV8 (Salmonella typhimurium (strain LT2 / SGSC1412 / ATCC 700720))
Go to UniProtKB:  Q8ZNV8
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
ZN
Query on ZN

Download SDF File 
Download CCD File 
A
ZINC ION
Zn
PTFCDOFLOPIGGS-UHFFFAOYSA-N
 Ligand Interaction
SO4
Query on SO4

Download SDF File 
Download CCD File 
A
SULFATE ION
O4 S
QAOWNCQODCNURD-UHFFFAOYSA-L
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.93 Å
  • R-Value Free: 0.228 
  • R-Value Work: 0.206 
  • Space Group: P 63
Unit Cell:
Length (Å)Angle (°)
a = 141.680α = 90.00
b = 141.680β = 90.00
c = 30.858γ = 120.00
Software Package:
Software NamePurpose
MOLREPphasing
DENZOdata reduction
SCALEPACKdata scaling
REFMACrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2011-04-27
    Type: Initial release
  • Version 1.1: 2011-08-31
    Type: Database references, Version format compliance