Insights into a dual function amide oxidase/macrocyclase from lankacidin biosynthesis

• Published in: Nature communications 2018-09, Vol.9 (1), p.3998-3998, Article 3998
• Main Authors: Dorival, Jonathan, Risser, Fanny, Jacob, Christophe, Collin, Sabrina, Dräger, Gerald, Paris, Cédric, Chagot, Benjamin, Kirschning, Andreas, Gruez, Arnaud, Weissman, Kira J.
• Format: Article
• Language: English
• Subjects: 631/45/173; 631/45/535/1266; 631/92/60; 82/80; 82/83; Amides - chemistry; Amides - metabolism; Amine oxidase (flavin-containing); Amino Acid Sequence; Antibiotics; Architecture; Assembly lines; Bacterial Proteins - chemistry; Bacterial Proteins - genetics; Bacterial Proteins - metabolism; Biocatalysis; Biochemistry; Biochemistry, Molecular Biology; Biosynthesis; Biosynthetic Pathways - genetics; Catalysis; Catalytic activity; Dimerization; Enzymes; Humanities and Social Sciences; Life Sciences; Macrolides - chemical synthesis; Macrolides - chemistry; Macrolides - metabolism; Models, Chemical; Models, Molecular; Molecular Structure; multidisciplinary; Oxidase; Oxidation; Oxidoreductases Acting on CH-NH Group Donors - chemistry; Oxidoreductases Acting on CH-NH Group Donors - genetics; Oxidoreductases Acting on CH-NH Group Donors - metabolism; Protein Conformation; Protein Multimerization; Proteins; Science; Science (multidisciplinary); Sequence Homology, Amino Acid; Streptomyces - enzymology; Streptomyces - genetics; Streptomyces - metabolism; Structural Biology; Substrate Specificity; Substrates; Synthetic biology; Weight
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-018-06323-w

Acquisition of new catalytic activity is a relatively rare evolutionary event. A striking example appears in the pathway to the antibiotic lankacidin, as a monoamine oxidase (MAO) family member, LkcE, catalyzes both an unusual amide oxidation, and a subsequent intramolecular Mannich reaction to form the polyketide macrocycle. We report evidence here for the molecular basis for this dual activity. The reaction sequence involves several essential active site residues and a conformational change likely comprising an interdomain hinge movement. These features, which have not previously been described in the MAO family, both depend on a unique dimerization mode relative to all structurally characterized members. Taken together, these data add weight to the idea that designing new multifunctional enzymes may require changes in both architecture and catalytic machinery. Encouragingly, however, our data also show LkcE to bind alternative substrates, supporting its potential utility as a general cyclization catalyst in synthetic biology. The monoamine oxidase family member LkcE is an enzyme from the lankacidin polyketide biosynthetic pathway, where it catalyzes an amide oxidation followed by an intramolecular Mannich reaction, yielding the polyketide macrocycle. Here the authors characterize LkcE and present several of its crystal structures, which explains the unusual dual activity of LkcE.