|
Figure 2.
Figure 2. Type 1 calcium ion-binding sites. Ca^2+ in type 1
sites in G1 and in G4 is coordinated by Glu167 of actin (cyan).
In severin domain 2,[16.] the structure of which was elucidated
in the absence of actin, a water molecule (purple) completes the
coordination sphere of Ca^2+. This site is characterized by
coordination by a conserved aspartic acid at the C-terminal end
of the H1 helix and carbonyl oxygen atoms five and seven
residues further along the polypeptide chain. Calcium ions are
shown as gold spheres.
|
