Mallostery: Filling a niche between quality and metabolic control.

To be, or not to be … What determines the destruction of a protein in response to metabolic cues? In the current issue of JBC, Wangeline and Hampton shed new light on this existential question by studying the classic case of HMGCR (Hmg2 in yeast), the rate-limiting step in sterol synthesis, and find a metabolic cue that causes "allosteric misfolding" and subsequent destruction of the protein, a concept they name mallostery.