1F4Q

CRYSTAL STRUCTURE OF APO GRANCALCIN

1F4Q の概要

• エントリーDOI: 10.2210/pdb1f4q/pdb
• 関連するPDBエントリー: 1F4O
• 分子名称: GRANCALCIN (2 entities in total)
• 機能のキーワード: penta-ef-hand protein, calcium binding protein, metal transport
• 由来する生物種: Homo sapiens (human)
• 細胞内の位置: Cytoplasm: P28676
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 37488.39

構造登録者

Jia, J.,Han, Q.,Borregaard, N.,Lollike, K.,Cygler, M. (登録日: 2000-06-08, 公開日: 2000-09-27, 最終更新日: 2024-02-07)

主引用文献

Jia, J.,Han, Q.,Borregaard, N.,Lollike, K.,Cygler, M.
Crystal structure of human grancalcin, a member of the penta-EF-hand protein family.
J.Mol.Biol., 300:1271-1281, 2000

PubMed Abstract: Grancalcin is a Ca(2+)-binding protein expressed at high level in neutrophils. It belongs to the PEF family, proteins containing five EF-hand motifs and which are known to associate with membranes in Ca(2+)-dependent manner. Prototypic members of this family are Ca(2+)-binding domains of calpain. Our recent finding that grancalcin interacts with L-plastin, a protein known to have actin bundling activity, suggests that grancalcin may play a role in regulation of adherence and migration of neutrophils. The structure of human grancalcin has been determined at 1.9 A resolution in the absence of calcium (R-factor of 0.212 and R-free of 0.249) and at 2. 5 A resolution in the presence of calcium (R-factor of 0.226 and R-free of 0.281). The molecule is predominantly alpha-helical: it contains eight alpha-helices and only two short stretches of two-stranded beta-sheets between the loops of paired EF-hands. Grancalcin forms dimers through the association of the unpaired EF5 hands in a manner similar to that observed in calpain, confirming this mode of association as a paradigm for the PEF family. Only one Ca(2+) was found per dimer under crystallization conditions that included CaCl(2). This cation binds to EF3 in one molecule, while this site in the second molecule of the dimer is unoccupied. This unoccupied site shows higher mobility. The structure determined in the presence of calcium, although does not represent a fully Ca(2+)-loaded form, suggests that calcium induces rather small conformational rearrangements. Comparison with calpain suggests further that the relatively small magnitude of conformational changes invoked by calcium alone may be a characteristic feature of the PEF family. Moreover, the largest differences are localized to the EF1, thus supporting the notion that calcium signaling occurs through this portion of the molecule and that it may involve the N-terminal Gly/Pro rich segment. Electrostatic potential distribution shows significant differences between grancalcin and calpain domain VI demonstrating their distinct character.

PubMed: 10903868
DOI: 10.1006/jmbi.2000.3925

実験手法

X-RAY DIFFRACTION (1.9 Å)