1J7O

Solution structure of Calcium-calmodulin N-terminal domain

Summary for 1J7O

• Entry DOI: 10.2210/pdb1j7o/pdb
• Related: 1CLL 1EXR 1F70
• Descriptor: Calmodulin, CALCIUM ION (2 entities in total)
• Functional Keywords: ef hands, calcium binding, helix bundle, mini beta strand, metal binding protein
• Biological source: Homo sapiens (human)
• Cellular location: Cytoplasm, cytoskeleton, spindle: P62158
• Total number of polymer chains: 1
• Total formula weight: 8534.51

Authors

Chou, J.J.,Klee, C.B.,Bax, A. (deposition date: 2001-05-17, release date: 2001-11-07, Last modification date: 2024-05-22)

Primary citation

Chou, J.J.,Li, S.,Klee, C.B.,Bax, A.
Solution structure of Ca(2+)-calmodulin reveals flexible hand-like properties of its domains.
Nat.Struct.Biol., 8:990-997, 2001

PubMed Abstract: The solution structure of Ca(2+)-ligated calmodulin is determined from residual dipolar couplings measured in a liquid crystalline medium and from a large number of heteronuclear J couplings for defining side chains. Although the C-terminal domain solution structure is similar to the X-ray crystal structure, the EF hands of the N-terminal domain are considerably less open. The substantial differences in interhelical angles correspond to negligible changes in short interproton distances and, therefore, cannot be identified by comparison of NOEs and X-ray data. NOE analysis, however, excludes a two-state equilibrium in which the closed apo conformation is partially populated in the Ca(2+)-ligated state. The difference between the crystal and solution structures of Ca(2+)-calmodulin indicates considerable backbone plasticity within the domains of calmodulin, which is key to their ability to bind a wide range of targets. In contrast, the vast majority of side chains making up the target binding surface are locked into the same chi(1) rotameric states as in complexes with target peptide.

PubMed: 11685248
DOI: 10.1038/nsb1101-990

Experimental method

SOLUTION NMR