A molecular dynamics study of Ca(2+)-calmodulin: evidence of interdomain coupling and structural collapse on the nanosecond timescale.

ABSTRACT: A 20-ns molecular dynamics simulation of Ca(2+)-calmodulin (CaM) in explicit solvent is described. Within 5 ns, the extended crystal structure adopts a compact shape similar in dimension to complexes of CaM and target peptides but with a substantially different orientation between the N- and C-terminal domains. Significant interactions are observed between the terminal domains in this compact state, which are mediated through the same regions of CaM that bind to target peptides derived from protein kinases and most other target proteins. The process of compaction is driven by the loss of helical structure in two separate regions between residues 75-79 and 82-86, the latter being driven by unfavorable electrostatic interactions between acidic residues. In the first 5 ns of the simulation, a

SUBMITTER: Shepherd CM 

PROVIDER: S-EPMC1304488 | biostudies-literature | 2004 Aug

REPOSITORIES: biostudies-literature