PDBsum entry 2zfd

Signaling protein/transferase

PDB id: 2zfd

Contents

Protein chains

183 a.a. *

116 a.a. *

Ligands

ACY ×2

Metals

_CA ×6

Waters ×236

* Residue conservation analysis

PDB id:

2zfd

Name:

Signaling protein/transferase

Title:

The crystal structure of plant specific calcium binding protein atcbl2 in complex with the regulatory domain of atcipk14

Structure:

Calcineurin b-like protein 2. Chain: a. Synonym: sos3-like calcium-binding protein 1. Engineered: yes. Putative uncharacterized protein t20l15_90. Chain: b. Fragment: unp residues 305-427. Synonym: putative uncharacterized protein at5g01820, cbl-interacting protein kinase 14, serine/threonine protein kinase.

Source:

Arabidopsis thaliana. Thale cress. Organism_taxid: 3702. Gene: cbl2. Expressed in: escherichia coli. Expression_system_taxid: 562. Gene: cipk14.

Resolution:

1.20Å R-factor: 0.180 R-free: 0.192

Authors:

M.Akaboshi,H.Hashimoto,H.Ishida,N.Koizumi,M.Sato,T.Shimizu

Key ref:

M.Akaboshi et al. (2008). The crystal structure of plant-specific calcium-binding protein AtCBL2 in complex with the regulatory domain of AtCIPK14. J Mol Biol, 377, 246-257. PubMed id: 18237745 DOI: 10.1016/j.jmb.2008.01.006

Date:

29-Dec-07 Release date: 19-Feb-08

Protein chain

Q8LAS7  (CNBL2_ARATH) -  Calcineurin B-like protein 2 from Arabidopsis thaliana

Seq: 226 a.a.

Struc: 183 a.a.

Protein chain

Q9LZW4  (CIPKE_ARATH) -  CBL-interacting serine/threonine-protein kinase 14 from Arabidopsis thaliana

Seq: 442 a.a.

Struc: 116 a.a.

Enzyme reactions

• Enzyme class: Chain 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.2008.01.006

J Mol Biol 377:246-257 (2008)

PubMed id: 18237745

The crystal structure of plant-specific calcium-binding protein AtCBL2 in complex with the regulatory domain of AtCIPK14.

M.Akaboshi, H.Hashimoto, H.Ishida, S.Saijo, N.Koizumi, M.Sato, T.Shimizu.

ABSTRACT

Calcium signals mediate a multitude of plant responses to external stimuli. Calcineurin B-like (CBL) proteins and their target kinases, CBL-interacting protein kinases (CIPKs), represent important relays in plant calcium signaling. CBL interacts with CIPK through a conserved motif (NAF/FISL motif) within the C-terminal regulatory domain. To better understand the functional role of the CBL-CIPK system, we determined the crystal structure of AtCBL2 in complex with the regulatory domain of AtCIPK14 at 1.2 A resolution. The NAF/FISL motif is inserted into a hydrophobic crevice within AtCBL2, accompanied by a large displacement of the helices and loop on the opposite side of the NAF/FISL motif from the C-terminal region, which shields the hydrophobic crevice in free form. Ca(2+) are coordinated within four EF hands in AtCBL2 in bound form. This calcium coordination pattern differs from that in the structure of the SOS3-SOS2 complex previously reported. Structural comparison of the two structures shows that the recognition of CBL by CIPK is performed in a similar manner, but inherent interactions confer binding affinity and specificity.

Selected figure(s)

Figure 3.
Fig. 3. Representation of the four EF-hand motifs (EF-1, EF-2, EF-3, and EF-4). (a) Amino acid residues involved in calcium coordination are shown. Calcium ions and water molecules are represented as big and small balls, respectively. (b) Superimposed structures of each EF hand in the bound and free forms. EF-1 and EF-4 are well superimposed, but EF-2 and EF-3 are deviated.

Figure 4.
Fig. 4. Interactions between AtCBL2 and the regulatory domain of AtCIPK14. (a) The N-lobe, C-lobe, and C-terminal region interacting with the NAF/FISL motif are in yellow, green, and blue, respectively. The NAF/FISL motif is represented as a red ribbon. The NAF/FISL motif binds along the crevice of AtCBL2. Dashed lines correspond to hydrogen bonds. (b) Close-up view of the interaction between the CBL–NAF/FISL motif and the regulatory domain. Hydrogen bonds are shown with dashed lines (stereo). (c) Pull-down assay of His-tagged AtCBL2 with the regulatory domain of AtCIPK14 of wild type and mutants.

The above figures are reprinted by permission from Elsevier: J Mol Biol (2008, 377, 246-257) copyright 2008.

Figures were selected by an automated process.