2CT9

The crystal structure of calcineurin B homologous proein 1 (CHP1)

Summary for 2CT9

• Entry DOI: 10.2210/pdb2ct9/pdb
• Descriptor: Calcium-binding protein p22, CALCIUM ION (3 entities in total)
• Functional Keywords: ef-hand, calcium binding protein, metal binding protein
• Biological source: Rattus norvegicus (Norway rat)
• Cellular location: Cytoplasm: P61023
• Total number of polymer chains: 2
• Total formula weight: 48140.05

Authors

Naoe, Y.,Arita, K.,Hashimoto, H.,Kanazawa, H.,Sato, M.,Shimizu, T. (deposition date: 2005-05-23, release date: 2005-07-05, Last modification date: 2024-03-13)

Primary citation

Naoe, Y.,Arita, K.,Hashimoto, H.,Kanazawa, H.,Sato, M.,Shimizu, T.
Structural characterization of calcineurin B homologous protein 1
J.Biol.Chem., 280:32372-32378, 2005

PubMed 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.

PubMed: 15987692
DOI: 10.1074/jbc.M503390200

Experimental method

X-RAY DIFFRACTION (2.2 Å)