Yeasts are complex organisms that may become the workhorses of biofuel production. To move yeasts into this larger role, scientists need to understand the genetic machinery that leads to the production of complex molecules like the iron-binding molecule pulcherrimin in budding yeasts. Scientists revealed a four-gene cluster associated with pulcherrimin production. Further tests revealed likely functions for each of the genes: two biosynthetic enzymes, a transporter, and a transcription factor involved in both biosynthesis and transport.