1XO5

Crystal structure of CIB1, an EF-hand, integrin and kinase-binding protein

Summary for 1XO5

• Entry DOI: 10.2210/pdb1xo5/pdb
• Descriptor: Calcium and integrin-binding protein 1, CALCIUM ION (3 entities in total)
• Functional Keywords: calcium and integrin binding, ef-hand, kinase interacting protein, calmyrin, calcium-binding protein
• Biological source: Homo sapiens (human)
• Cellular location: Membrane; Lipid-anchor. Isoform 2: Cytoplasm, perinuclear region : Q99828
• Total number of polymer chains: 2
• Total formula weight: 42281.60

Authors

Gentry, H.R.,Singer, A.U.,Betts, L.,Yang, C.,Ferrara, J.D.,Parise, L.V.,Sondek, J. (deposition date: 2004-10-05, release date: 2004-12-07, Last modification date: 2024-02-14)

Primary citation

Gentry, H.R.,Singer, A.U.,Betts, L.,Yang, C.,Ferrara, J.D.,Sondek, J.,Parise, L.V.
Structural and Biochemical Characterization of CIB1 Delineates a New Family of EF-hand-containing Proteins
J.Biol.Chem., 280:8407-8415, 2005

PubMed Abstract: CIB1 (CIB) is an EF-hand-containing protein that binds multiple effector proteins, including the platelet alphaIIbbeta3 integrin and several serine/threonine kinases and potentially modulates their function. The crystal structure for Ca(2+)-bound CIB1 has been determined at 2.0 A resolution and reveals a compact alpha-helical protein containing four EF-hands, the last two of which bind calcium ions in the standard fashion seen in many other EF-hand proteins. CIB1 shares high structural similarity with calcineurin B and the neuronal calcium sensor (NCS) family of EF-hand-containing proteins. Most importantly, like calcineurin B and NCS proteins, which possess a large hydrophobic pocket necessary for ligand binding, CIB1 contains a hydrophobic pocket that has been implicated in ligand binding by previous mutational analysis. However, unlike several NCS proteins, Ca(2+)-bound CIB1 is largely monomeric whether bound to a relevant peptide ligand or ligand-free. Differences in structure, oligomeric state, and phylogeny define a new family of CIB1-related proteins that extends from arthropods to humans.

PubMed: 15574431
DOI: 10.1074/jbc.M411515200

Experimental method

X-RAY DIFFRACTION (1.99 Å)