1K95

Crystal structure of des(1-52)grancalcin with bound calcium

Summary for 1K95

• Entry DOI: 10.2210/pdb1k95/pdb
• Descriptor: GRANCALCIN (2 entities in total)
• Functional Keywords: penta-ef-hand protein, calcium binding protein, metal binding protein
• Biological source: Homo sapiens (human)
• Cellular location: Cytoplasm : P28676
• Total number of polymer chains: 1
• Total formula weight: 18771.22

Authors

Jia, J.,Borregaard, N.,Lollike, K.,Cygler, M. (deposition date: 2001-10-26, release date: 2001-12-07, Last modification date: 2023-08-16)

Primary citation

Jia, J.,Borregaard, N.,Lollike, K.,Cygler, M.
Structure of Ca(2+)-loaded human grancalcin.
Acta Crystallogr.,Sect.D, 57:1843-1849, 2001

PubMed Abstract: Grancalcin is a cytosolic Ca(2+)-binding protein originally identified in human neutrophils. It belongs to a new class of EF-hand proteins, called PEF proteins, which contain five EF-hand motifs. At the N-terminus of grancalcin there is a approximately 50 residue-long segment rich in glycines and prolines. The fifth EF-hand, unpaired within the monomer, provides a means for dimerization through pairing with its counterpart in a second molecule. The structure of full-length grancalcin in the apo form and with one EF3 within the dimer occupied by a Ca(2+) ion have been determined. Although the N-terminal segment was present in the molecule, this part was disordered in the crystals. Here, the structure of a truncated form of grancalcin, which is lacking 52 N-terminal residues, in the presence and absence of Ca(2+) is presented. In the Ca(2+)-bound form the ions are found in the EF1 and EF3 hands. Binding of Ca(2+) to these two EF hands produces only minor conformational changes, mostly within the EF1 Ca(2+)-binding loop. This observation supports the hypothesis, formulated on the basis of the structure of a homologous protein ALG-2 which shows significant differences in the orientation of EF4 and EF5 compared with grancalcin, that calcium is a necessary factor but not sufficient alone for inducing a significant conformational change in PEF proteins.

PubMed: 11717497
DOI: 10.1107/S0907444901016511

Experimental method

X-RAY DIFFRACTION (1.9 Å)