PDBsum entry 2k0e

Metal binding protein

PDB id: 2k0e

Contents

Protein chain

148 a.a. *

Metals

_CA ×4

* Residue conservation analysis

PDB id:

2k0e

Name:

Metal binding protein

Title:

A coupled equilibrium shift mechanism in calmodulin-mediated signal transduction

Structure:

Calmodulin. Chain: a. Engineered: yes

Source:

Homo sapiens. Human. Gene: calm1, calm, cam, cam1. Expressed in: escherichia coli.

NMR struc:

160 models

Authors:

J.Gsponer,J.Christodoulou,A.Cavalli,J.M.Bui,B.Richter,C.M.Dobson, M.Vendruscolo

Key ref:

J.Gsponer et al. (2008). A coupled equilibrium shift mechanism in calmodulin-mediated signal transduction. Structure, 16, 736-746. PubMed id: 18462678 DOI: 10.1016/j.str.2008.02.017

Date:

02-Feb-08 Release date: 10-Jun-08

Protein chain

P0DP23  (CALM1_HUMAN) -  Calmodulin-1 from Homo sapiens

Seq: 149 a.a.

Struc: 148 a.a.

DOI no: 10.1016/j.str.2008.02.017

Structure 16:736-746 (2008)

PubMed id: 18462678

A coupled equilibrium shift mechanism in calmodulin-mediated signal transduction.

J.Gsponer, J.Christodoulou, A.Cavalli, J.M.Bui, B.Richter, C.M.Dobson, M.Vendruscolo.

ABSTRACT

We used nuclear magnetic resonance data to determine ensembles of conformations representing the structure and dynamics of calmodulin (CaM) in the calcium-bound state (Ca(2+)-CaM) and in the state bound to myosin light chain kinase (CaM-MLCK). These ensembles reveal that the Ca(2+)-CaM state includes a range of structures similar to those present when CaM is bound to MLCK. Detailed analysis of the ensembles demonstrates that correlated motions within the Ca(2+)-CaM state direct the structural fluctuations toward complex-like substates. This phenomenon enables initial ligation of MLCK at the C-terminal domain of CaM and induces a population shift among the substates accessible to the N-terminal domain, thus giving rise to the cooperativity associated with binding. Based on these results and the combination of modern free energy landscape theory with classical allostery models, we suggest that a coupled equilibrium shift mechanism controls the efficient binding of CaM to a wide range of ligands.

Selected figure(s)

Figure 4.
Figure 4.

Figure 7.
Figure 7. Comparison between FRET-Derived Distances and the Corresponding Ones Calculated from the Ca^2+-CaM Ensemble
The distance distribution measured by FRET between a donor fluorophore and acceptor fluorophore on residues 34 in the NTD and 110 in the CTD of Ca^2+-CaM is shown in red; the distance distribution calculated from the Ca^2+-CaM ensemble is shown in black. See Johnson, 2006.

The above figures are reprinted from an Open Access publication published by Cell Press: Structure (2008, 16, 736-746) copyright 2008.

Figures were selected by an automated process.