PDBsum entry 2aao

Transferase

PDB id: 2aao

Contents

Protein chains

147 a.a. *

140 a.a. *

Metals

_CA ×9

Waters ×153

* Residue conservation analysis

PDB id:

2aao

Name:

Transferase

Title:

Regulatory apparatus of calcium dependent protein kinase from arabidopsis thaliana

Structure:

Calcium-dependent protein kinase, isoform ak1. Chain: a, b. Synonym: cdpk. Engineered: yes

Source:

Arabidopsis thaliana. Thale cress. Organism_taxid: 3702. Gene: ak1. Expressed in: escherichia coli bl21(de3). Expression_system_taxid: 469008.

Biol. unit:

Dimer (from PQS)

Resolution:

2.00Å R-factor: 0.278 R-free: 0.254

Authors:

V.Chandran,E.J.Stollar,K.Lindorff-Larsen,J.F.Harper,W.J.Chazin, C.M.Dobson,B.F.Luisi,J.Christodoulou

Key ref:

V.Chandran et al. (2006). Structure of the regulatory apparatus of a calcium-dependent protein kinase (CDPK): a novel mode of calmodulin-target recognition. J Mol Biol, 357, 400-410. PubMed id: 16430916 DOI: 10.1016/j.jmb.2005.11.093

Date:

13-Jul-05 Release date: 27-Dec-05

Protein chain

Q06850  (CDPK1_ARATH) -  Calcium-dependent protein kinase 1 from Arabidopsis thaliana

Seq: 610 a.a.

Struc: 147 a.a.

Protein chain

Q06850  (CDPK1_ARATH) -  Calcium-dependent protein kinase 1 from Arabidopsis thaliana

Seq: 610 a.a.

Struc: 140 a.a.

Enzyme reactions

• Enzyme class: Chains A, B: E.C.2.7.11.1 - non-specific serine/threonine protein kinase.
• Reaction:
  1. L-seryl-[protein] + ATP = O-phospho-L-seryl-[protein] + ADP + H⁺
  2. L-threonyl-[protein] + ATP = O-phospho-L-threonyl-[protein] + ADP + H⁺

Molecule diagrams generated from .mol files obtained from the KEGG ftp site

reference

DOI no: 10.1016/j.jmb.2005.11.093

J Mol Biol 357:400-410 (2006)

PubMed id: 16430916

Structure of the regulatory apparatus of a calcium-dependent protein kinase (CDPK): a novel mode of calmodulin-target recognition.

V.Chandran, E.J.Stollar, K.Lindorff-Larsen, J.F.Harper, W.J.Chazin, C.M.Dobson, B.F.Luisi, J.Christodoulou.

ABSTRACT

Calcium-dependent protein kinases (CDPKs) are a class of calcium-binding sensory proteins that are found in plants and certain protozoa, including the causative agent of malaria, Plasmodium falciparum. CDPKs have diverse regulatory functions, including involvement in the triggering of the lytic cycle of malarial infection. CDPKs contain an autoinhibitory junction (J) region whose calcium-dependent interaction with the tethered regulatory calmodulin-like domain (CaM-LD) activates the catalytic kinase domain. We report here the X-ray crystal structure of the J-CaM-LD region of CDPK from Arabidopsis thaliana (AtCPK1), determined to 2.0 A resolution using multiple-wavelength anomalous dispersion (MAD). The structure reveals a symmetric dimer of calcium-bound J-CaM-LD with domain-swap interactions, in which the J region of one protomer interacts extensively with the carboxy-terminal EF-hand domain (C-lobe) of the partner protomer. However, as the J-CaM-LD is monomeric in solution, the activated monomer was modelled to account for the intra-molecular recognition of the two domains. While the J-CaM-LD segment mimics certain aspects of target motif recognition by CaM other features are specific to CDPKs, in particular the combination of the strong interaction between the N and C-lobes of the CaM-LD and the exclusive use of only the C-lobe in the recognition of the covalently tethered target region. Combined with our previous observations showing that there is likely to be strong interactions between this tethered J region and the CaM-LD even at basal Ca(2+) concentrations, the new structural data indicate that the response to calcium of CDPKs is clearly unique among the CaM family.

Selected figure(s)

Figure 1.
Figure 1. (a) Schematic of the domain structure of CDPK. The regulatory apparatus is comprised of the Junction region (J) and the calmodulin-like domain (CaM-LD). (b) Ribbon diagram of the crystal structure of the regulatory apparatus of CDPK showing the homodimeric organization observed. The two molecules are coloured in red and blue, respectively. The J region of each monomer depicted in a darker colour is observed interacting with the partner molecule in a domain swap interaction. The inset depicts these interactions schematically. (c) Overlay of the amino-terminal and carboxyl-terminal calcium-binding sub-domains of the CaM-LD (N-lobe and C-lobe, respectively). The root-mean-square deviation (RMSD) of C^α atoms for the overlay is 0.9 Å. The models are complete except for residues 428–432, 556–562, 588–591 from protomer A and residues 428–432, 551–566, 588–591 from protomer B.

Figure 3.
Figure 3. (a) Stereo view of the interaction of the J region with the C-lobe of the CaM-LD. The J region is shown in red and the C-lobe in blue. (b) A schematic summary of the key interactions of the helical J region with the CaM-LD (boxed). The J region interacts exclusively with the C-lobe.

The above figures are reprinted by permission from Elsevier: J Mol Biol (2006, 357, 400-410) copyright 2006.

Figures were selected by an automated process.