Fumarase C catalyses the stereo-specific interconversion of fumarate to L-malate as part of the Kreb's cycle. The full-length protein forms a tetramer with visible globular shape. FumaraseC_C is the C-terminal 65 residues referred to as domain 3. The core of the molecule consists of a bundle of 20 alpha-helices from the five-helix bundle of domain 2. The projections from the core of the tetramer are generated from domains 1 and 3 of each subunit [1]. FumaraseC_C does not appear to be part of either the active site or the activation site but is helical in structure forming a little bundle.

1: Crystallographic studies of the catalytic and a second site in fumarase C from Escherichia coli. Weaver T, Banaszak L; Biochemistry. 1996;35:13955-13965. PMID:8909293