Complement regulation at the molecular level: the structure of decay-accelerating factor

P Lukacik, P Roversi, J White, D Esser… - Proceedings of the …, 2004 - National Acad Sciences
P Lukacik, P Roversi, J White, D Esser, GP Smith, J Billington, PA Williams, PM Rudd…
Proceedings of the National Academy of Sciences, 2004National Acad Sciences
The human complement regulator CD55 is a key molecule protecting self-cells from
complement-mediated lysis. X-ray diffraction and analytical ultracentrifugation data reveal a
rod-like arrangement of four short consensus repeat (SCR) domains in both the crystal and
solution. The stalk linking the four SCR domains to the glycosylphosphatidylinositol anchor
is extended by the addition of 11 highly charged O-glycans and positions the domains an
estimated 177 Å above the membrane. Mutation mapping and hydrophobic potential …
The human complement regulator CD55 is a key molecule protecting self-cells from complement-mediated lysis. X-ray diffraction and analytical ultracentrifugation data reveal a rod-like arrangement of four short consensus repeat (SCR) domains in both the crystal and solution. The stalk linking the four SCR domains to the glycosylphosphatidylinositol anchor is extended by the addition of 11 highly charged O-glycans and positions the domains an estimated 177 Å above the membrane. Mutation mapping and hydrophobic potential analysis suggest that the interaction with the convertase, and thus complement regulation, depends on the burial of a hydrophobic patch centered on the linker between SCR domains 2 and 3.
National Acad Sciences