The okaramine chemical structure. The diagram shows how the OkaE enzyme (represented conceptually by the test tube) acts like a specialized LEGO connector, catalyzing the formation of a crucial four-ring structure (highlighted) by joining two specific carbon atoms. Source: Biosynthesis of Complex Indole Alkaloids: Elucidation of the Concise Pathway of Okaramines. Diagram adapted by: Lin Ting-Hsien and Chang Yu-Chen