Work

Structure of Human Complement C8, a Precursor to Membrane Attack

Year: 2010

Type: article

Abstract: Complement component C8 plays a pivotal role in the formation of the membrane attack complex (MAC), an important antibacterial immune effector. C8 initiates membrane penetration and coordinates MAC pore formation. High-resolution structures of C8 subunits have provided some insight into the function of the C8 heterotrimer; however, there is no structural information describing how the intersubunit organization facilitates MAC assembly. We have determined the structure of C8 by electron microscopy and fitted the C8α-MACPF (membrane attack complex/perforin)-C8γ co-crystal structure and a homology model for C8β-MACPF into the density. Here, we demonstrate that both the C8γ protrusion and the C8α-MACPF region that inserts into the membrane upon activation are accessible.

Source: Journal of Molecular Biology

DOI: 10.1016/j.jmb.2010.10.031

Authors: Doryen Bubeck, Pietro Roversi, Rossen Donev, B. Paul Morgan, Oscar Llorca, Susan M. Lea