Chemoenzymatic synthesis of thiazolyl peptide natural products featuring an enzyme-catalyzed formal [4 + 2] cycloaddition.
Thiocillins from Bacillus cereus ATCC 14579 are members of the well-known thiazolyl peptide class of natural product antibiotics, the biosynthesis of which has recently been shown to proceed via post-translational modification of ribosomally encoded precursor peptides. It has long been hypothesized that the final step of thiazolyl peptide biosynthesis involves a formal [4 + 2] cycloaddition between two dehydroalanines, a unique transformation that had eluded enzymatic characterization. Here we demonstrate that TclM, a single enzyme from the thiocillin biosynthetic pathway, catalyzes this transformation. To facilitate characterization of this new class of enzyme, we have developed a combined chemical and biological route to the complex peptide substrate, relying on chemical synthesis of a modified C-terminal fragment and coupling to a 38-residue leader peptide by means of native chemical ligation (NCL). This strategy, combined with active enzyme, provides a new chemoenzymatic route to this promising class of antibiotics.
†Division of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States.
Walter J
WJ
Wever
†Division of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States.
Jonathan W
JW
Bogart
‡Boyce Thompson Institute and Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States.
Joshua A
JA
Baccile
§Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States.
Andrew N
AN
Chan
‡Boyce Thompson Institute and Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States.
Frank C
FC
Schroeder
†Division of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States.
Albert A
AA
Bowers
D000595:Amino Acid Sequence; D055162:Biocatalysis; D001688:Biological Products / Q000138:chemical synthesis* / Q000737:chemistry; D061565:Cycloaddition Reaction; D004798:Enzymes / Q000378:metabolism*; D008969:Molecular Sequence Data; D010455:Peptides / Q000138:chemical synthesis* / Q000737:chemistry
D001688:Biological Products; D004798:Enzymes; D010455:Peptides; C012574:thiocillin