This is the N-terminal domain of the disulfide bond isomerase DsbC. The whole molecule is V-shaped, where each arm is a DsbC monomer of two domains linked by a hinge; and the N-termini of each monomer join to form the dimer interface at the base of the V, so are vital for dimerisation [1]. DsbC is required for disulfide bond formation and functions as a disulfide bond isomerase during oxidative protein-folding in bacterial periplasm. It also has chaperone activity [2].

1: Crystal structure of the protein disulfide bond isomerase, DsbC, from Escherichia coli. McCarthy AA, Haebel PW, Torronen A, Rybin V, Baker EN, Metcalf P; Nat Struct Biol. 2000;7:196-199. PMID:10700276

2: Copper stress causes an in vivo requirement for the Escherichia coli disulfide isomerase DsbC. Hiniker A, Collet JF, Bardwell JC; J Biol Chem. 2005;280:33785-33791. PMID:16087673