2L7L

Solution structure of Ca2+/calmodulin complexed with a peptide representing the calmodulin-binding domain of calmodulin kinase I

Summary for 2L7L

• Entry DOI: 10.2210/pdb2l7l/pdb
• Related: 1MXE
• NMR Information: BMRB: 17360
• Descriptor: Calmodulin, Calcium/calmodulin-dependent protein kinase type 1, CALCIUM ION (3 entities in total)
• Functional Keywords: calmodulin complex, calmodulin-peptide complex, camki, metal binding protein-transferase complex, metal binding protein/transferase
• Biological source: Homo sapiens (human); More
• Cellular location: Cytoplasm: Q63450
• Total number of polymer chains: 2
• Total formula weight: 19487.78

Authors

Gifford, J.L.,Ishida, H.,Vogel, H.J. (deposition date: 2010-12-13, release date: 2011-05-18, Last modification date: 2024-05-15)

Primary citation

Gifford, J.L.,Ishida, H.,Vogel, H.J.
Fast methionine-based solution structure determination of calcium-calmodulin complexes.
J.Biomol.Nmr, 50:71-81, 2011

PubMed Abstract: Here we present a novel NMR method for the structure determination of calcium-calmodulin (Ca(2+)-CaM)-peptide complexes from a limited set of experimental restraints. A comparison of solved CaM-peptide structures reveals invariability in CaM's backbone conformation and a structural plasticity in CaM's domain orientation enabled by a flexible linker. Knowing this, the collection and analysis of an extensive set of NOESY spectra is redundant. Although RDCs can define CaM domain orientation in the complex, they lack the translational information required to position the domains on the bound peptide and highlight the necessity of intermolecular NOEs. Here we employ a specific isotope labeling strategy in which the role of methionine in CaM-peptide interactions is exploited to collect these critical NOEs. By (1)H, (13)C-labeling the methyl groups of deuterated methionine against a (2)H, (12)C background, we can acquire a (13)C-edited NOESY characterized by simplified, easily analyzable spectra. Together with measured CaM backbone H(N)-N RDCs and intrapeptide NOE-based distances, these intermolecular NOEs provide restraints for a low temperature torsion-angle dynamics and simulated annealing protocol used to calculate the complex structure. We have applied our method to a CaM complex previously solved through X-ray crystallography: Ca(2+)-CaM bound to the CaM kinase I peptide (PDB code: 1MXE). The resulting structure has a backbone RMSD of 1.6 Å to that previously published. We have also used this test complex to investigate the importance of homologous model selection on the calculated outcome. In addition to having application for fast complex structure determination, this method can be used to determine the structures of difficult complexes characterized by chemical shift overlap and broad signals for which the traditional method based on the use of fully (13)C, (15)N-labeled CaM fails.

PubMed: 21360154
DOI: 10.1007/s10858-011-9495-3

Experimental method

SOLUTION NMR