1k95
Crystal structure of des(1-52)grancalcin with bound calcium
Structural highlights
FunctionGRAN_HUMAN Calcium-binding protein that may play a role in the adhesion of neutrophils to fibronectin. May play a role in the formation of focal adhesions. Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedGrancalcin 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. 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[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References | ||||||||||||||||||
