PDBsum entry 2kn2

Metal binding protein

PDB id: 2kn2

Contents

Protein chain

92 a.a. *

Metals

_CA ×2

* Residue conservation analysis

PDB id:

2kn2

Name:

Metal binding protein

Title:

Solution structure of thE C-terminal domain of soybean calmodulin isoform 4 fused with the calmodulin-binding domain of ntmkp1

Structure:

Calmodulin. Chain: a. Fragment: unp residues 79-150. Engineered: yes

Source:

Glycine max. Soybeans. Organism_taxid: 3847. Gene: scam-4. Expressed in: escherichia coli. Expression_system_taxid: 562. Other_details: sumo fusion

NMR struc:

30 models

Authors:

H.Ishida,M.Rainaldi,H.J.Vogel

Key ref:

H.Ishida et al. (2009). Structural studies of soybean calmodulin isoform 4 bound to the calmodulin-binding domain of tobacco mitogen-activated protein kinase phosphatase-1 provide insights into a sequential target binding mode. J Biol Chem, 284, 28292-28305. PubMed id: 19667066 DOI: 10.1074/jbc.M109.025080

Date:

12-Aug-09 Release date: 25-Aug-09

Protein chain

Q39890  (Q39890_SOYBN) -  Calmodulin from Glycine max

Seq: 150 a.a.

Struc: 92 a.a.*

* PDB and UniProt seqs differ at 3 residue positions (black crosses)

DOI no: 10.1074/jbc.M109.025080

J Biol Chem 284:28292-28305 (2009)

PubMed id: 19667066

Structural studies of soybean calmodulin isoform 4 bound to the calmodulin-binding domain of tobacco mitogen-activated protein kinase phosphatase-1 provide insights into a sequential target binding mode.

H.Ishida, M.Rainaldi, H.J.Vogel.

ABSTRACT

The calcium regulatory protein calmodulin (CaM) binds in a calcium-dependent manner to numerous target proteins. The calmodulin-binding domain (CaMBD) region of Nicotiana tabacum MAPK phosphatase has an amino acid sequence that does not resemble the CaMBD of any other known Ca(2+)-CaM-binding proteins. Using a unique fusion protein strategy, we have been able to obtain a high resolution solution structure of the complex of soybean Ca(2+)-CaM4 (SCaM4) and this CaMBD. Complete isotope labeling of both parts of the complex in the fusion protein greatly facilitated the structure determination by NMR. The 12-residue CaMBD region was found to bind exclusively to the C-lobe of SCaM4. A specific Trp and Leu side chain are utilized to facilitate strong binding through a novel "double anchor" motif. Moreover, the orientation of the helical peptide on the surface of Ca(2+)-SCaM4 is distinct from other known complexes. The N-lobe of Ca(2+)-SCaM4 in the complex remains free for additional interactions and could possibly act as a calcium-dependent adapter protein. Signaling through the MAPK pathway and increases in intracellular Ca(2+) are both hallmarks of the plant stress response, and our data support the notion that coordination of these responses may occur through the formation of a unique CaM-MAPK phosphatase multiprotein complex.

Selected figure(s)

Figure 4.
a, backbones of 30 structures of SCaM4CT-NtMKP1 are superimposed for the well-folded region (residue 80–163). The SCaM4CT and NtMKP1 domain are shown in navy and yellow, respectively, while the poly-Gly linker region is shown in gray. b, ribbon representations of the structure with the lowest energy. The hydrophobic side chains of Trp^157, Leu^160, and Phe^164 are displayed.

Figure 5.
a, local interactions between SCaM4CT residues and the anchor residues of the NtMKP1 domain, Trp^157 and Leu^160. The side chains of the SCaM4CT and NtMKP1 domains are colored in purple and green, respectively. b, schematic showing observed NOEs between SCaM4CT and NtMKP1 domain.

The above figures are reprinted by permission from the ASBMB: J Biol Chem (2009, 284, 28292-28305) copyright 2009.

Figures were selected by an automated process.