HelixConstraint A28 L31 0.896 StrandConstraint C40 V41 0.738 HelixConstraint L74 M81 0.757 HelixConstraint R101 Y109 0.71 HelixConstraint S117 F122 0.784 HelixConstraint N135 Q143 0.796 HelixConstraint Y145 Q147 0.761