Open AccessChemoenzymatic Synthesis of Thiazolyl Peptide Natural Products Featuring an Enzyme-Catalyzed Formal [4 + 2] Cycloaddition
Author(s) -
Walter J. Wever,
Jonathan W. Bogart,
Joshua A. Baccile,
Andrew N. Chan,
Frank C. Schroeder,
A. Bowers
Publication year - 2015
Publication title -
journal of the american chemical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.115
H-Index - 612
eISSN - 1520-5126
pISSN - 0002-7863
DOI - 10.1021/jacs.5b00940
Subject(s) - chemistry , peptide , enzyme , biosynthesis , peptide synthesis , cycloaddition , chemical ligation , residue (chemistry) , peptide biosynthesis , combinatorial chemistry , chemical synthesis , natural product , stereochemistry , chemical transformation , bacillus cereus , native chemical ligation , biochemistry , catalysis , bacteria , organic chemistry , cysteine , rna , in vitro , gene , ribosome , genetics , biology
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.