Background: In the Caryophyllaceae, cyclic peptides (CP) are biosynthesized from linear precursors via an unknown pathway. Results: Two protease-like enzymes are involved in precursor processing. Conclusion: A serine protease-like enzyme was recruited for the cyclization step in CP biosynthesis. Significance: This represents a very significant advance in our understanding of the mode and evolution of CP biosynthesis in plants.

Short peptide tags genetically fused to recombinant proteins have been widely used to facilitate detection or purification without the need to develop specific procedures. In general, an ideal affinity tag would allow the efficient purification of tagged proteins in high yield, without affecting its function. Here, we describe the purification steps to purify a recombinant polyhistidine-tagged glucosyltransferase from Centella asiatica using immobilized metal affinity chromatography.