Located N-terminal to the wolframin OB-fold domain, this region could represent an extension to the core of the OB fold domain. The observed conserved cysteine residues could contribute to disulfide-bond-mediated cross-linking in calcium-stores regulation.

1: Functional Innovation in the Evolution of the Calcium-Dependent System of the Eukaryotic Endoplasmic Reticulum. Schaffer DE, Iyer LM, Burroughs AM, Aravind L; Front Genet. 2020;11:34. PMID:32117448