PDBsum entry 2ct9

Metal binding protein

PDB id: 2ct9

Contents

Protein chains

185 a.a. *

198 a.a. *

Metals

_CA ×4

Waters ×153

* Residue conservation analysis

PDB id:

2ct9

Name:

Metal binding protein

Title:

The crystal structure of calcineurin b homologous proein 1 (chp1)

Structure:

Calcium-binding protein p22. Chain: a, b. Synonym: calcineurin b homologous protein 1, calcium-binding protein chp, calcineurin homologous protein. Engineered: yes

Source:

Rattus norvegicus. Norway rat. Organism_taxid: 10116. Expressed in: escherichia coli. Expression_system_taxid: 562.

Biol. unit:

Dimer (from PQS)

Resolution:

2.20Å R-factor: 0.219 R-free: 0.268

Authors:

Y.Naoe,K.Arita,H.Hashimoto,H.Kanazawa,M.Sato,T.Shimizu

Key ref:

Y.Naoe et al. (2005). Structural characterization of calcineurin B homologous protein 1. J Biol Chem, 280, 32372-32378. PubMed id: 15987692 DOI: 10.1074/jbc.M503390200

Date:

23-May-05 Release date: 05-Jul-05

Protein chain

P61023  (CHP1_RAT) -  Calcineurin B homologous protein 1 from Rattus norvegicus

Seq: 195 a.a.

Struc: 185 a.a.

Protein chain

P61023  (CHP1_RAT) -  Calcineurin B homologous protein 1 from Rattus norvegicus

Seq: 195 a.a.

Struc: 198 a.a.

Enzyme reactions

• Enzyme class: Chains A, B: E.C.?

DOI no: 10.1074/jbc.M503390200

J Biol Chem 280:32372-32378 (2005)

PubMed id: 15987692

Structural characterization of calcineurin B homologous protein 1.

Y.Naoe, K.Arita, H.Hashimoto, H.Kanazawa, M.Sato, T.Shimizu.

ABSTRACT

Calcineurin B homologous protein 1 (CHP1), also known as p22, is a calcium-binding EF-hand protein that plays a role in membrane trafficking. It binds to multiple effector proteins, including Na(+)/H(+) exchangers, a serine/threonine kinase, and calcineurin, potentially modulating their function. The crystal structure of calcium-bound CHP1 from rat has been determined at 2.2 Angstroms of resolution. The molecule has a compact alpha-helical structure containing four EF-hands. The overall folding topology of the protein is similar to that of the regulatory B subunit of calcineurin and to that of calcium- and integrin-binding protein. The calcium ion is coordinated in typical fashion in the third and fourth EF-hands, but the first and second EF-hands contain no calcium ion. The first EF-hand is maintained by internal interactions, and the second EF-hand is stabilized by hydrophobic interactions. CHP1 contains a hydrophobic pocket on the opposite side of the protein to the EF-hands that has been implicated in ligand binding.

Selected figure(s)

Figure 2.
FIGURE 2. Overall structure of CHP1. a, ribbon representation of secondary structure elements. -Helices are colored blue, and calcium ions are depicted by yellow balls. The -helix derived from the vector is colored green. b, ribbon representation of the structure of CHP1 superimposed on that of CNB. CHP1 and CNB are represented as blue and red ribbons, respectively. The figure was generated by superimposing the -helices of the C-lobes. These are shown in pale blue and red. N- and C-terminal helices ( A and J) are omitted for clarity. The angle of rotation between the N-terminal domains of CHP1 and CNB is 20°.

Figure 3.
FIGURE 3. Representation of the four EF-hand motifs (EF-1, EF-2, EF-3, EF-4). a, calcium-bound EF-hand motifs (EF-3 and EF-4). Calcium ions and water molecules are represented as yellow and red balls, respectively. An omit map, contoured at the 7 level around each calcium ion, is superimposed. Amino acid residues involved in the calcium coordination are shown. b, calcium-unbound EF-hand motifs (EF-1 and EF-2). Non-covalent interactions within EF-hands are represented as dotted lines. In EF-2, residues forming the hydrophobic core are also shown.

The above figures are reprinted by permission from the ASBMB: J Biol Chem (2005, 280, 32372-32378) copyright 2005.

Figures were selected by an automated process.