Methyltransferases from RiPP pathways: shaping the landscape of natural product chemistry

• Maria-Paula Schröder,
• Isabel P.-M. Pfeiffer and
• Silja Mordhorst

Beilstein J. Org. Chem. 2024, 20, 1652–1670, doi:10.3762/bjoc.20.147

• [RMSD: 8.152 Å (109 to 109 atoms)], demonstrating the structural diversity among O-MTs (Figure 5). Streptomyces bottropensis produces various bottromycins, including bottromycin A2 (Figure 4) [79]. The precursor peptide consists of an N-terminal core and a rare C-terminal follower region. The

• biosynthesis of bottromycin involves several methylations, catalysed by four different MTs encoded in the BGC. Gomez-Escribano et al. named the BGC in which the MTs are encoded bmb and proposed their putative function [80]. Huo et al. named the same BGC bot and experimentally determined the function of the MTs

• . BmbA/BotOMT is the only O-MT involved in the biosynthesis of bottromycin [81]. It O-methylates the aspartate by transforming its carboxylic acid group to a methyl ester in the ultimate step in biosynthesis [79]. The remaining methylations are catalysed by C-MTs, which will be addressed in a following

Biosynthetic origin of butyrolactol A, an antifungal polyketide produced by a marine-derived Streptomyces

• Enjuro Harunari,
• Hisayuki Komaki and
• Yasuhiro Igarashi

Beilstein J. Org. Chem. 2017, 13, 441–450, doi:10.3762/bjoc.13.47

• -27). The origin of the tert-butyl group in polyketide biosynthesis is still unknown, however, the tert-butyl functionality of bottromycin and polytheonamide was shown to be produced by radical C-methylation of the isopropyl group of valine [31][32]. By analogy, the tert-butyl portion of 1 was most

Cyclisation mechanisms in the biosynthesis of ribosomally synthesised and post-translationally modified peptides

• Andrew W. Truman

Beilstein J. Org. Chem. 2016, 12, 1250–1268, doi:10.3762/bjoc.12.120

• contains the natural product precursor (Figure 1). The bottromycin precursor peptide represents a notable exception as it features an N-terminal core peptide and a C-terminal follower peptide [10][11][12][13]. The core peptide is post-translationally modified and cleaved from the leader peptide to yield a

• for a number of characterised secondary metabolite pathways. For example, the bottromycin gene cluster encodes two stand-alone YcaO domain proteins that have been postulated to participate in heterocyclisation reactions [10][11][12][13]. Lanthionine bond formation in lanthipeptides Lanthipeptides

Synthetic studies towards bottromycin

• Stefanie Ackermann,
• Hans-Georg Lerchen,
• Dieter Häbich,
• Angelika Ullrich and
• Uli Kazmaier

Beilstein J. Org. Chem. 2012, 8, 1652–1656, doi:10.3762/bjoc.8.189

• reactions are described as an excellent synthetic tool for the synthesis of sterically highly hindered endothiopeptides. S-Methylation and subsequent amidine formation can be carried out in an inter- as well as in an intramolecular fashion. The intramolecular approach allows the synthesis of the bottromycin

• ring system in a straightforward manner. Keywords: amidines; antibiotics; bottromycin; peptides; thiopeptides; Ugi reactions; Introduction Natural products are excellent sources as lead structures for the development of new antibiotics. Over millions of years microorganisms, such as bacteria and

• fermentation broth of Streptomyces bottropensis, called bottromycin [4][5][6]. This antibiotic inhibits the growth of a wide range of microorganisms by interfering with their protein biosynthesis [7][8][9][10][11][12]. In 1965 Nakamura et al. isolated closely related antibiotics from the strain Streptomyces No