1mxe
From Proteopedia
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|PDB= 1mxe |SIZE=350|CAPTION= <scene name='initialview01'>1mxe</scene>, resolution 1.70Å | |PDB= 1mxe |SIZE=350|CAPTION= <scene name='initialview01'>1mxe</scene>, resolution 1.70Å | ||
|SITE= | |SITE= | ||
| - | |LIGAND= <scene name='pdbligand=CA:CALCIUM ION'>CA</scene> | + | |LIGAND= <scene name='pdbligand=CA:CALCIUM+ION'>CA</scene> |
| - | |ACTIVITY= [http://en.wikipedia.org/wiki/Calcium/calmodulin-dependent_protein_kinase Calcium/calmodulin-dependent protein kinase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.7.11.17 2.7.11.17] | + | |ACTIVITY= <span class='plainlinks'>[http://en.wikipedia.org/wiki/Calcium/calmodulin-dependent_protein_kinase Calcium/calmodulin-dependent protein kinase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.7.11.17 2.7.11.17] </span> |
|GENE= | |GENE= | ||
| + | |DOMAIN= | ||
| + | |RELATEDENTRY= | ||
| + | |RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1mxe FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1mxe OCA], [http://www.ebi.ac.uk/pdbsum/1mxe PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=1mxe RCSB]</span> | ||
}} | }} | ||
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[[Category: Martin, S R.]] | [[Category: Martin, S R.]] | ||
[[Category: Smerdon, S J.]] | [[Category: Smerdon, S J.]] | ||
| - | [[Category: CA]] | ||
[[Category: calmodulin]] | [[Category: calmodulin]] | ||
[[Category: calmodulin-pepide complex]] | [[Category: calmodulin-pepide complex]] | ||
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[[Category: xray]] | [[Category: xray]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun Mar 30 22:22:31 2008'' |
Revision as of 19:22, 30 March 2008
| |||||||
| , resolution 1.70Å | |||||||
|---|---|---|---|---|---|---|---|
| Ligands: | |||||||
| Activity: | Calcium/calmodulin-dependent protein kinase, with EC number 2.7.11.17 | ||||||
| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
Structure of the Complex of Calmodulin with the Target Sequence of CaMKI
Overview
Calcium-saturated calmodulin (CaM) directly activates CaM-dependent protein kinase I (CaMKI) by binding to a region in the C-terminal regulatory sequence of the enzyme to relieve autoinhibition. The structure of CaM in a high-affinity complex with a 25-residue peptide of CaMKI (residues 294-318) has been determined by X-ray crystallography at 1.7 A resolution. Upon complex formation, the CaMKI peptide adopts an alpha-helical conformation, while changes in the CaM domain linker enable both its N- and C-domains to wrap around the peptide helix. Target peptide residues Trp-303 (interacting with the CaM C-domain) and Met-316 (with the CaM N-domain) define the mode of binding as 1-14. In addition, two basic patches on the peptide form complementary charge interactions with CaM. The CaM-peptide affinity is approximately 1 pM, compared with 30 nM for the CaM-kinase complex, indicating that activation of autoinhibited CaMKI by CaM requires a costly energetic disruption of the interactions between the CaM-binding sequence and the rest of the enzyme. We present biochemical and structural evidence indicating the involvement of both CaM domains in the activation process: while the C-domain exhibits tight binding toward the regulatory sequence, the N-domain is necessary for activation. Our crystal structure also enables us to identify the full CaM-binding sequence. Residues Lys-296 and Phe-298 from the target peptide interact directly with CaM, demonstrating overlap between the autoinhibitory and CaM-binding sequences. Thus, the kinase activation mechanism involves the binding of CaM to residues associated with the inhibitory pseudosubstrate sequence.
About this Structure
1MXE is a Protein complex structure of sequences from Drosophila melanogaster. Full crystallographic information is available from OCA.
Reference
Structure of the complex of calmodulin with the target sequence of calmodulin-dependent protein kinase I: studies of the kinase activation mechanism., Clapperton JA, Martin SR, Smerdon SJ, Gamblin SJ, Bayley PM, Biochemistry. 2002 Dec 17;41(50):14669-79. PMID:12475216
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