figure6

Ca+ control of Gelsolin Function

1. The lower affinity human S1-actin Ca+ binding site. S1 is show in red and actin in grey. The position of S3relative to S1 is shown in yellow. The Lys319 from S3 occupied a position similar to that of Glu-167 from actin. Therefore, the abscence of Ca+ may push the S3 away and make the binding possibility.
2. The high affinity human S1-actin Ca+ binding site. The C-terminal portion of the S1 structure is shown in pink Wrapping around the Ca+ ion. The structure of this portion lies in S2 from whole gelsolin is shown in green. Therefore, the binding of Ca+ may be the force to rotate the peptide bond and make the binding possibility.