1U00

HscA substrate binding domain complexed with the IscU recognition peptide ELPPVKIHC


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.95 Å
  • R-Value Free: 0.210 
  • R-Value Work: 0.174 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Crystal Structure of the Molecular Chaperone HscA Substrate Binding Domain Complexed with the IscU Recognition Peptide ELPPVKIHC.

Cupp-Vickery, J.R.Peterson, J.C.Ta, D.T.Vickery, L.E.

(2004) J.Mol.Biol. 342: 1265-1278

  • DOI: 10.1016/j.jmb.2004.07.025

  • PubMed Abstract: 
  • HscA, a specialized bacterial Hsp70-class molecular chaperone, interacts with the iron-sulfur cluster assembly protein IscU by recognizing a conserved LPPVK sequence motif. We report the crystal structure of the substrate-binding domain of HscA (SBD, ...

    HscA, a specialized bacterial Hsp70-class molecular chaperone, interacts with the iron-sulfur cluster assembly protein IscU by recognizing a conserved LPPVK sequence motif. We report the crystal structure of the substrate-binding domain of HscA (SBD, residues 389-616) from Escherichia coli bound to an IscU-derived peptide, ELPPVKIHC. The crystals belong to the space group I222 and contain a single molecule in the asymmetric unit. Molecular replacement with the E.coli DnaK(SBD) model was used for phasing, and the HscA(SBD)-peptide model was refined to Rfactor=17.4% (Rfree=21.0%) at 1.95 A resolution. The overall structure of HscA(SBD) is similar to that of DnaK(SBD), although the alpha-helical subdomain (residues 506-613) is shifted up to 10 A relative to the beta-sandwich subdomain (residues 389-498) when compared to DnaK(SBD). The ELPPVKIHC peptide is bound in an extended conformation in a hydrophobic cleft in the beta-subdomain, which appears to be solvent-accessible via a narrow passageway between the alpha and beta-subdomains. The bound peptide is positioned in the reverse orientation of that observed in the DnaK(SBD)-NRLLLTG peptide complex placing the N and C termini of the peptide on opposite sides of the HscA(SBD) relative to the DnaK(SBD) complex. Modeling of the peptide in the DnaK-like forward orientation suggests that differences in hydrogen bonding interactions in the binding cleft and electrostatic interactions involving surface residues near the cleft contribute to the observed directional preference.


    Organizational Affiliation

    Department of Physiology and Biophysics, University of California, Irvine, CA 92697, USA. jvickery@uci.edu




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Chaperone protein hscA
A
227Escherichia coli (strain K12)Mutation(s): 0 
Gene Names: hscA (hsc)
Find proteins for P0A6Z1 (Escherichia coli (strain K12))
Go to UniProtKB:  P0A6Z1
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
IscU recognition peptide
P
9N/AMutation(s): 0 
Protein Feature View is not available: No corresponding UniProt sequence found.
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.95 Å
  • R-Value Free: 0.210 
  • R-Value Work: 0.174 
  • Space Group: I 2 2 2
Unit Cell:
Length (Å)Angle (°)
a = 62.761α = 90.00
b = 83.340β = 90.00
c = 128.734γ = 90.00
Software Package:
Software NamePurpose
CCP4data scaling
REFMACrefinement
MOSFLMdata reduction
MOLREPphasing

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2004-10-05
    Type: Initial release
  • Version 1.1: 2008-04-30
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance