The Kaposi's sarcoma virus SOX protein causes overgrowth of this structure, and its formation is directed by a tripartite sig
The Kaposi's sarcoma virus SOX protein causes overgrowth of this structure, and its formation is directed by a tripartite signal that includes efficiency and positioning elements.  HEX, CPE, and Pumilio-binding elements participate in their formation, and the association of a namesake binding factor with these structures recruits eIF-4G.  The transferrin receptor and several histone components use a stem-loop rather than this structure.  In plant mitochondria, long ones are destabilizing, but more commonly, the lengthening of these structures enhances the stability of the molecules to which they are attached and promotes translation.  For 10 points, name this structure found on the 3' (three prime) end of most mRNAs which consists of a long string of adenosines.
The Kaposi's sarcoma virus SOX protein causes overgrowth of this structure, and its formation is directed by a tripartite signal that includes efficiency and positioning elements.  
poly-A tail