This is the C-terminal domain of Regulator of microtubule dynamics proteins 1-3 (RMD1-3) which consists of alpha-helical repeats. These are microtubule-binding proteins. RMD3 is involved in cellular calcium homeostasis regulation, and it may participate in differentiation and apoptosis of keratinocytes [1]. RMD1 from C. elegans functions in chromosome segregation [2].

1: VAPB interacts with the mitochondrial protein PTPIP51 to regulate calcium homeostasis. De Vos KJ, Morotz GM, Stoica R, Tudor EL, Lau KF, Ackerley S, Warley A, Shaw CE, Miller CC; Hum Mol Genet. 2012;21:1299-1311. PMID:22131369

2: RMD-1, a novel microtubule-associated protein, functions in chromosome segregation in Caenorhabditis elegans. Oishi K, Okano H, Sawa H; J Cell Biol. 2007;179:1149-1162. PMID:18070910