Calcium-induced structural changes and domain autonomy in calmodulin

Nat Struct Biol. 1995 Sep;2(9):777-83. doi: 10.1038/nsb0995-777.


We have determined the solution structures of the apo and (Ca2+)2 forms of the carboxy-terminal domain of calmodulin using multidimensional heteronuclear nuclear magnetic resonance spectroscopy. The results show that both forms adopt well-defined structures with essentially equal secondary structure. A comparison of the structures of the two forms shows that Ca2+ binding causes major rearrangements of the secondary structure elements with changes in inter-residue distances of up to 15 A and exposure of the hydrophobic interior of the four-helix bundle. Comparisons with previously determined high-resolution X-ray structures and models of calmodulin indicate that this domain is structurally autonomous.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Calcium / pharmacology*
  • Calmodulin / chemistry*
  • Calmodulin / metabolism*
  • Cattle
  • Crystallography, X-Ray
  • Magnetic Resonance Spectroscopy / methods
  • Protein Conformation
  • Solutions
  • Structure-Activity Relationship


  • Calmodulin
  • Solutions
  • Calcium