1GJY

The X-ray structure of the Sorcin Calcium Binding Domain (SCBD) provides insight into the phosphorylation and calcium dependent processess


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.2 Å
  • R-Value Free: 0.296 
  • R-Value Work: 0.232 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

The Crystal Structure of the Sorcin Calcium Binding Domain Provides a Model of Ca(2+)-Dependent Processes in the Full-Length Protein

Ilari, A.Johnson, K.Nastopoulos, V.Verzili, D.Zamparelli, C.Colotti, G.Tsernoglou, D.Chiancone, E.

(2002) J.Mol.Biol. 317: 447

  • DOI: 10.1006/jmbi.2002.5417
  • Also Cited By: 2JC2

  • PubMed Abstract: 
  • Sorcin is a 21.6 kDa calcium binding protein, expressed in a number of mammalian tissues that belongs to the small, recently identified penta-EF-hand (PEF) family. Like all members of this family, sorcin undergoes a Ca2+-dependent translocation from ...

    Sorcin is a 21.6 kDa calcium binding protein, expressed in a number of mammalian tissues that belongs to the small, recently identified penta-EF-hand (PEF) family. Like all members of this family, sorcin undergoes a Ca2+-dependent translocation from cytosol to membranes where it binds to target proteins. For sorcin, the targets differ in different tissues, indicating that it takes part in a number of Ca2+-regulated processes. The sorcin monomer is organized in two domains like in all PEF proteins: a flexible, hydrophobic, glycine-rich N-terminal region and a calcium binding C-terminal domain. In vitro, the PEF proteins are dimeric in their Ca2+-free form, but have a marked tendency to precipitate when bound to calcium. Stabilization of the dimeric structure is achieved by pairing of the uneven EF-hand, EF5. Sorcin can also form tetramers at acid pH. The sorcin calcium binding domain (SCBD, residues 33-198) expressed in Escherichia coli was crystallized in the Ca2+-free form. The structure was solved by molecular replacement and was refined to 2.2 A with a crystallographic R-factor of 22.4 %. Interestingly, the asymmetric unit contains two dimers. The structure of the SCBD leads to a model that explains the solution properties and describes the Ca2+-induced conformational changes. Phosphorylation studies show that the N-terminal domain hinders phosphorylation of SCBD, i.e. the rate of phosphorylation increased twofold in the absence of the N-terminal region. In addition, previous fluorescence studies indicated that hydrophobic residues are exposed to solvent upon Ca2+ binding to full-length sorcin. The model accounts for these data by proposing that Ca2+ binding weakens the interactions between the two domains and leads to their reorientation, which exposes hydrophobic regions facilitating the Ca2+-dependent binding to target proteins at or near membranes.


    Related Citations: 
    • Two Different Crystal Forms of Sorcin, a Penta-EF-Hand Ca2+-Binding Protein
      Nastopoulos, V.,Ilari, A.,Colotti, G.,Zamparelli, C.,Verzili, D.,Chiancone, E.,Tsernoglou, D.
      (2001) Acta Crystallogr.,Sect.D 57: 862


    Organizational Affiliation

    CNR, Centro Studio sulla Biologia Molecolare and Dipartimento di Scienze Biochimiche, Università La Sapienza, P.le Aldo Moro 5, Roma, 00185, Italy.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
SORCIN
A, B, C, D
167Cricetulus griseusGene Names: SRI
Find proteins for P05044 (Cricetulus griseus)
Go to Gene View: SRI
Go to UniProtKB:  P05044
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
SO4
Query on SO4

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

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.2 Å
  • R-Value Free: 0.296 
  • R-Value Work: 0.232 
  • Space Group: C 1 2 1
Unit Cell:
Length (Å)Angle (°)
a = 130.925α = 90.00
b = 103.847β = 117.96
c = 78.546γ = 90.00
Software Package:
Software NamePurpose
DENZOdata reduction
SCALEPACKdata scaling
X-PLORrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2002-04-05
    Type: Initial release
  • Version 1.1: 2011-05-08
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance