||Blanchard, H., Grochulski, P., Li, Y., Arthur, S.C., Davies, P.L., Elce, J.S., Cygler, M. Structure of a calpain Ca2+-binding domain reveals a novel EF-hand and Ca2+-induced conformational changes (1997) Nat Struct Biol 4, 532-538.
||Melanie R. Nelson, The Scripps Research Institute, Molecular Biology
|Depositor's e-mail address:
||Melanie R. Nelson (firstname.lastname@example.org)
||Calcium binds to EF-1, EF-2, and EF-3 at 1 mM Ca2+. At higher calcium concentrations (200 mM), a fourth calcium binds. This calcium binds atypically to the end of loop 4, and has eight oxygen ligands. It was displaced by yttterbium when the crystals were soaked with the heavy atom solution. There are no significant differences in the structures solved the low calcium and high calcium environment. The authors conlcude that this fourth binding site is unlikely to be occupied under physiological conditions.