 |
PDBsum entry 3qrx
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Metal binding protein/toxin
|
PDB id
|
|
|
|
3qrx
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
References listed in PDB file
|
|
|
Key reference
|
|
|
Title
|
|
The structure, Molecular dynamics, And energetics of centrin-Melittin complex.
|
|
|
Authors
|
|
L.D.E.L. .V.Sosa,
E.Alfaro,
J.Santiago,
D.Narváez,
M.C.Rosado,
A.Rodríguez,
A.M.Gómez,
E.R.Schreiter,
B.Pastrana-Ríos.
|
|
|
Ref.
|
|
Proteins, 2011,
79,
3132-3143.
|
|
|
PubMed id
|
|
|
|
|
|
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 (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.
|
|
|
|
|
|
|
