2OV3

Crystal structure of 138-173 ZnuA deletion mutant plus zinc bound


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.40 Å
  • R-Value Free: 0.275 
  • R-Value Work: 0.227 
  • R-Value Observed: 0.227 

wwPDB Validation   3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

Possible Regulatory Role for the Histidine-Rich Loop in the Zinc Transport Protein, ZnuA

Wei, B.Randich, A.M.Bhattacharyya-Pakrasi, M.Pakrasi, H.B.Smith, T.J.

(2007) Biochemistry 46: 8734-8743

  • DOI: 10.1021/bi700763w
  • Primary Citation of Related Structures:  
    2OV3, 2OV1

  • PubMed Abstract: 
  • A number of bacterial metal transporters belong to the ABC transporter family. To better understand the structural determinants of metal selectivity of one such transporter, we previously determined the structure of the periplasmic domain of a zinc t ...

    A number of bacterial metal transporters belong to the ABC transporter family. To better understand the structural determinants of metal selectivity of one such transporter, we previously determined the structure of the periplasmic domain of a zinc transporter, ZnuA, from Synechocystis 6803 and found that ZnuA binds zinc via three histidines. Unique to these ABC zinc transporters, ZnuA has a highly charged and mobile loop that protrudes from the protein in the vicinity of the metal binding site that we had suggested might facilitate zinc acquisition. To further examine the function of this loop, the structure and zinc binding properties of two ZnuA variants were determined. When the loop is entirely deleted, zinc still binds to the three histidines. However, unlike what was suggested from the structure of a similar solute binding protein, TroA, release of zinc occurs concomitantly with large conformational changes in two of the three chelating histidines. These structural results combined with isothermal titration calorimetry data demonstrate that there are at least two classes of zinc binding sites: the high-affinity site in the cleft between the two domains and at least one additional site on the flexible loop. This loop has approximately 100-fold weaker affinity for zinc than the high-affinity zinc binding site, and its deletion does not affect the high-affinity site. From these results, we suggest that this region might be a sensor for high periplasmic levels of zinc.


    Organizational Affiliation

    Donald Danforth Plant Science Center, 975 North Warson Road, St. Louis, Missouri 63132, USA.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Periplasmic binding protein component of an ABC type zinc uptake transporterA260Synechocystis sp.Mutation(s): 0 
Gene Names: zntC
Find proteins for P73085 (Synechocystis sp. (strain PCC 6803 / Kazusa))
Explore P73085 
Go to UniProtKB:  P73085
Protein Feature View
Expand
  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
ZN
Query on ZN

Download Ideal Coordinates CCD File 
A
ZINC ION
Zn
PTFCDOFLOPIGGS-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.40 Å
  • R-Value Free: 0.275 
  • R-Value Work: 0.227 
  • R-Value Observed: 0.227 
  • Space Group: C 2 2 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 62.329α = 90
b = 76.982β = 90
c = 127.311γ = 90
Software Package:
Software NamePurpose
CNSrefinement
PDB_EXTRACTdata extraction
PROTEUM PLUSdata collection
SAINTdata reduction
PROTEUM PLUSdata scaling
CNSphasing

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

  • Deposited Date: 2007-02-12 
  • Released Date: 2007-08-07 
  • Deposition Author(s): Smith, T.J., Wei, B.

Revision History 

  • Version 1.0: 2007-08-07
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Version format compliance
  • Version 1.2: 2017-08-16
    Changes: Refinement description, Source and taxonomy