This region is always found associated with Pfam:PF02141. It is predicted to form a globular domain [1]. Although not statistically supported it has been suggested that this domain may be similar to members of the Rho/Rac/Cdc42 GEF family [1]. This N-terminal region of DENN folds into a longin module, consisting of a central antiparallel beta-sheet layered between helix H1 and helices H2 and H3 (strands S1-S5). Rab35 interacts with dDENN via residues in helix 1 and in the loop S3-S4 [2].

1: uDENN, DENN, and dDENN: indissociable domains in Rab and MAP kinases signaling pathways. Levivier E, Goud B, Souchet M, Calmels TP, Mornon JP, Callebaut I; Biochem Biophys Res Commun 2001;287:688-695. PMID:11563850

2: Insights regarding guanine nucleotide exchange from the structure of a DENN-domain protein complexed with its Rab GTPase substrate. Wu X, Bradley MJ, Cai Y, Kummel D, De La Cruz EM, Barr FA, Reinisch KM; Proc Natl Acad Sci U S A. 2011;108:18672-18677. PMID:22065758