This is the N-terminal domain found in DsbG, a protein disulfide isomerase present in the periplasm of Helicobacter pylori. The formation of correct disulfide bonds is critical in the folding process of many secretory and membrane proteins in bacteria. Non-native disulfides are corrected by the isomerase DsbC, and, to a lesser extent, by DsbG. The N-terminal domain is involved in dimerization. The dimer interface of Helicobacter pylori's DsbG is stabilized by hydrophobic interactions and hydrogen bonds involving alpha 1, beta-3 to beta-4 loop, beta-4 and beta-4 to alpha-2 loop. This pattern of dimerization is similar to that of E. coli's DsbG [1].

1: Structural and functional characterization of Helicobacter pylori DsbG. Yoon JY, Kim J, Lee SJ, Kim HS, Im HN, Yoon HJ, Kim KH, Kim SJ, Han BW, Suh SW; FEBS Lett. 2011;585:3862-3867. PMID:22062156