2bbm
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SOLUTION STRUCTURE OF A CALMODULIN-TARGET PEPTIDE COMPLEX BY MULTIDIMENSIONAL NMR
OverviewOverview
The three-dimensional solution structure of the complex between, calcium-bound calmodulin (Ca(2+)-CaM) and a 26-residue synthetic peptide, comprising the CaM binding domain (residues 577 to 602) of skeletal muscle, myosin light chain kinase, has been determined using multidimensional, heteronuclear filtered and separated nuclear magnetic resonance, spectroscopy. The two domains of CaM (residues 6 to 73 and 83 to 146), remain essentially unchanged upon complexation. The long central helix, (residues 65 to 93), however, which connects the two domains in the, crystal structure of Ca(2+)-CaM, is disrupted into two helices connected, by a long flexible loop (residues 74 to 82), thereby enabling the two, domains to clamp residues 3 to 21 of the bound peptide, which adopt a, helical conformation. The overall structure of the complex is globular, approximating an ellipsoid of dimensions 47 by 32 by 30 angstroms. The, helical peptide is located in a hydrophobic channel that passes through, the center of the ellipsoid at an angle of approximately 45 degrees with, its long axis. The complex is mainly stabilized by hydrophobic, interactions which, from the CaM side, involve an unusually large number, of methionines. Key residues of the peptide are Trp4 and Phe17, which, serve to anchor the amino- and carboxyl-terminal halves of the peptide to, the carboxyl- and amino-terminal domains of CaM, respectively. Sequence, comparisons indicate that a number of peptides that bind CaM with high, affinity share this common feature containing either aromatic residues or, long-chain hydrophobic ones separated by a stretch of 12 residues, suggesting that they interact with CaM in a similar manner.
About this StructureAbout this Structure
2BBM is a Protein complex structure of sequences from Drosophila melanogaster with CA as ligand. The following page contains interesting information on the relation of 2BBM with [Calmodulin]. Full crystallographic information is available from OCA.
ReferenceReference
Solution structure of a calmodulin-target peptide complex by multidimensional NMR., Ikura M, Clore GM, Gronenborn AM, Zhu G, Klee CB, Bax A, Science. 1992 May 1;256(5057):632-8. PMID:1585175
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