1S6J

N-terminal Region of the Ca2+-saturated calcium regulatory domain (CLD) from Soybean Calcium-dependent Protein Kinase-alpha (CDPK)

Summary for 1S6J

• Entry DOI: 10.2210/pdb1s6j/pdb
• Related: 1S6I
• NMR Information: BMRB: 6103
• Descriptor: Calcium-dependent protein kinase SK5, CALCIUM ION (2 entities in total)
• Functional Keywords: ef-hand; helix-loop-helix; calcium-binding; calmodulin superfamily, transferase, plant protein
• Biological source: Glycine max (soybean)
• Total number of polymer chains: 1
• Total formula weight: 9722.76

Authors

Weljie, A.M.,Vogel, H.J. (deposition date: 2004-01-23, release date: 2004-12-21, Last modification date: 2024-05-22)

Primary citation

Weljie, A.M.,Gagne, S.M.,Vogel, H.J.
Solution Structure and Backbone Dynamics of the N-Terminal Region of the Calcium Regulatory Domain from Soybean Calcium-Dependent Protein Kinase alpha
Biochemistry, 42:15131-15140, 2004

PubMed Abstract: Ca(2+)-dependent protein kinases (CDPKs) are vital Ca(2+)-signaling proteins in plants and protists which have both a kinase domain and a self-contained calcium regulatory calmodulin-like domain (CLD). Despite being very similar to CaM (>40% identity) and sharing the same fold, recent biochemical and structural evidence suggests that the behavior of CLD is distinct from its namesake, calmodulin. In this study, NMR spectroscopy is employed to examine the structure and backbone dynamics of a 168 amino acid Ca(2+)-saturated construct of the CLD (NtH-CLD) in which almost the entire C-terminal domain is exchange broadened and not visible in the NMR spectra. Structural characterization of the N-terminal domain indicates that the first Ca(2+)-binding loop is significantly more open than in a recently reported structure of the CLD complexed with a putative intramolecular binding region (JD) in the CDPK. Backbone dynamics suggest that parts of the third helix exhibit unusually high mobility, and significant exchange, consistent with previous findings that this helix interacts with the C-terminal domain. Dynamics data also show that the "tether" region, consisting of the first 11 amino acids of CLD, is highly mobile and these residues exhibit distinctive beta-type secondary structure, which may help to position the JD and CLD. Finally, the unusual global dynamic behavior of the protein is rationalized on the basis of possible interdomain rearrangements and the highly variable environments of the C- and N-terminal domains.

PubMed: 15568805
DOI: 10.1021/bi048751r

Experimental method

SOLUTION NMR