Factor I-like modules (FIMs) are present in complement proteins C6, C7, and factor I, and participate in protein-protein interactions that critical to the progress of a complement-mediated immune response. Complement component C6 contains a FIM pair at the C-terminal, FIM1 ana FIM2, each of them consists of a small N-terminal FOLN subdomain and a larger C-terminal KAZAL domain (Pfam:PF18434) [1]. This entry represents the KAZAL domain of FIM1 [1].

1: Solution structure of factor I-like modules from complement C7 reveals a pair of follistatin domains in compact pseudosymmetric arrangement. Phelan MM, Thai CT, Soares DC, Ogata RT, Barlow PN, Bramham J; J Biol Chem. 2009;284:19637-19649. PMID:19419965

2: Structure of complement C6 suggests a mechanism for initiation and unidirectional, sequential assembly of membrane attack complex (MAC). Aleshin AE, Schraufstatter IU, Stec B, Bankston LA, Liddington RC, DiScipio RG; J Biol Chem. 2012;287:10210-10222. PMID:22267737