Solution structure of factor I-like modules from complement C7 reveals a pair of follistatin domains in compact pseudosymmetric arrangement.

ABSTRACT: Factor I-like modules (FIMs) of complement proteins C6, C7, and factor I participate in protein-protein interactions critical to the progress of a complement-mediated immune response to infections and other trauma. For instance, the carboxyl-terminal FIM pair of C7 (C7-FIMs) binds to the C345C domain of C5 and its activated product, C5b, during self-assembly of the cytolytic membrane-attack complex. FIMs share sequence similarity with follistatin domains (FDs) of known three-dimensional structure, suggesting that FIM structures could be reliably modeled. However, conflicting disulfide maps, inconsistent orientations of subdomains within FDs, and the presence of binding partners in all FD structures led us to determine the three-dimensional structure of C7-FIMs by NMR spectroscopy. The solu

SUBMITTER: Phelan MM 

PROVIDER: S-EPMC2740589 | biostudies-literature | 2009 Jul

REPOSITORIES: biostudies-literature