1k94
From Proteopedia
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Crystal structure of des(1-52)grancalcin with bound calcium
Contents |
Overview
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.
Disease
Known diseases associated with this structure: Cone dystrophy-3 OMIM:[600364], Hemolytic anemia due to gamma-glutamylcysteine synthetase deficiency OMIM:[606857]
About this Structure
1K94 is a Single protein structure of sequence from Homo sapiens with CA as ligand. Full crystallographic information is available from OCA.
Reference
Structure of Ca(2+)-loaded human grancalcin., Jia J, Borregaard N, Lollike K, Cygler M, Acta Crystallogr D Biol Crystallogr. 2001 Dec;57(Pt 12):1843-9. Epub 2001, Nov 21. PMID:11717497
Page seeded by OCA on Mon Nov 12 17:48:35 2007
