3QRX

Chlamydomonas reinhardtii centrin bound to melittin


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.2 Å
  • R-Value Free: 0.341 
  • R-Value Work: 0.291 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

The structure, molecular dynamics, and energetics of centrin-melittin complex.

Sosa Ldel, V.Alfaro, E.Santiago, J.Narvaez, D.Rosado, M.C.Rodriguez, A.Gomez, A.M.Schreiter, E.R.Pastrana-Rios, B.

(2011) Proteins 79: 3132-3143

  • DOI: 10.1002/prot.23142

  • PubMed Abstract: 
  • Centrin is a calcium binding protein (CaBP) belonging to the EF-hand superfamily. As with other proteins within this family, centrin is a calcium sensor with multiple biological target proteins. We chose to study Chlamydomonas reinhardtii centrin (Cr ...

    Centrin is a calcium binding protein (CaBP) belonging to the EF-hand superfamily. As with other proteins within this family, centrin is a calcium sensor with multiple biological target proteins. We chose to study Chlamydomonas reinhardtii centrin (Crcen) and its interaction with melittin (MLT) as a model for CaBP complexes due to its amphipathic properties. Our goal was to determine the molecular interactions that lead to centrin-MLT complex formation, their relative stability, and the conformational changes associated with the interaction, when compared to the single components. For this, we determined the thermodynamic parameters that define Crcen-MLT complex formation. Two-dimensional infrared (2D IR) correlation spectroscopy were used to study the amide I', I'*, and side chain bands for (13)C-Crcen, MLT, and the (13)C-Crcen-MLT complex. This approach resulted in the determination of MLT's increased helicity, while centrin was stabilized within the complex. Herein we provide the first complete molecular description of centrin-MLT complex formation and the dissociation process. Also, discussed is the first structure of a CaBP-MLT complex by X-ray crystallography, which shows that MLT has a different binding orientation than previously characterized centrin-bound peptides. Finally, all of the experimental results presented herein are consistent with centrin maintaining an extended conformation while interacting with MLT. The molecular implications of these results are: (1) the recognition of hydrophobic contacts as requirements for initial binding, (2) minimum electrostatic interactions within the C-terminal end of the peptide, and (3) van der Waals interactions within MLTs N-terminal end are required for complex formation.


    Organizational Affiliation

    Department of Chemistry, University of Puerto Rico, Mayag├╝ez, Puerto Rico 00681-9019.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Centrin
A
169Chlamydomonas reinhardtiiMutation(s): 0 
Find proteins for P05434 (Chlamydomonas reinhardtii)
Go to UniProtKB:  P05434
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
Melittin
B
26Apis melliferaMutation(s): 0 
Gene Names: MELT
Find proteins for P01501 (Apis mellifera)
Go to UniProtKB:  P01501
Small Molecules
Ligands 1 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
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.2 Å
  • R-Value Free: 0.341 
  • R-Value Work: 0.291 
  • Space Group: P 21 21 2
Unit Cell:
Length (Å)Angle (°)
a = 52.104α = 90.00
b = 114.426β = 90.00
c = 34.842γ = 90.00
Software Package:
Software NamePurpose
PHASERphasing
HKL-2000data scaling
CrystalCleardata collection
HKL-2000data reduction
REFMACrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

  • Deposited Date: 2011-02-18 
  • Released Date: 2011-10-26 
  • Deposition Author(s): Schreiter, E.R.

Revision History 

  • Version 1.0: 2011-10-26
    Type: Initial release
  • Version 1.1: 2013-03-20
    Type: Derived calculations