This domain is present in several proteins that are linked to the functions of GTPases in the Rap and Rab families. They could hence play important roles in multiple Ras-like GTPase signalling pathways. The domain is comprises six conserved regions, which in some proteins have considerable insertions between them. The domain core is thought to take up a predominantly alpha fold, with basic amino acids in regions A and D possibly playing a functional role in interactions with Ras GTPases [1].

1: RUN domains: a new family of domains involved in Ras-like GTPase signaling. Callebaut I, de Gunzburg J, Goud B, Mornon JP; Trends Biochem Sci 2001;26:79-83. PMID:11166556