Module 4: Figure EF-hand motif
Structural organization of the EF-hand.
The orientations of the two helices that make up the EF-hand resemble a finger and a thumb as illustrated on the right. The small loop connecting these two helices contains aspartate and glutamate residues that provide the carbonyl-group oxygen atoms to co-ordinate the Ca2+ ion. Reproduced, with permission, from the Annual Review of Biochemistry, Volume 45 © 1976 by Annual Reviews; http://www.annualreviews.org; see Kretsinger 1976.