Aims Actinobacteria are known to produce extracellular enzymes including DyPs. We set out to identify and characterize novel peroxidases from Streptomyces chartreusis NRRL 3882, because S. chartreusis belongs to the small group of actinobacteria with three different DyPs. Methods and Results The genome of the actinomycete S. chartreusis NRRL 3882 was mined for novel DyP‐type peroxidases. Three genes encoding for DyP‐type peroxidases were cloned and overexpressed in Escherichia coli. Subsequent characterization of the recombinant proteins included examination of operating conditions such as pH, temperature and H2O2 concentrations, as well as substrate spectrum. Despite their high sequence similarity, the enzymes named SCDYP1‐SCDYP3 presented distinct preferences regarding their operating conditions. They showed great divergence in H2O2 tolerance and stability, with SCDYP2 being most active at concentrations above 50 mmol l−1. Moreover, SCDYP1 and SCDYP3 preferred acidic pH (typical for DyP‐type peroxidases), whereas SCDYP2 was most active at pH 8. Conclusions Regarding the function of DyPs in nature, these results suggest that availability of different DyP variants with complementary activity profiles in one organism might convey evolutionary benefits. Significance and Impact of the Study DyP‐type peroxidases are able to degrade xenobiotic compounds and thus can be applied in biocatalysis and bioremediation. However, the native function of DyPs and the benefits for their producers largely remain to be elucidated.

Due to worldwide increasing resistances, there is a considerable need for antibacterial compounds with modes of action not yet realized in commercial antibiotics. One such promising structure is the acetyl-CoA carboxylase (ACC) inhibitor moiramide B which shows strong antibacterial activity against gram-positive bacteria such as Bacillus subtilis and weaker activities against gram-negative bacteria. However, the narrow structure-activity relationship of the pseudopeptide unit of moiramide B represents a formidable challenge for any optimization strategy.In contrast, the lipophilic fatty acid tail is considered an unspecific vehicle responsible only for the transport of moiramide into the bacterial cell. Here we show that the sorbic acid unit, in fact, is highly relevant for ACC inhibition. A hitherto undescribed sub-pocket at the end of the sorbic acid channel binds strongly aromatic rings and allows the development of moiramide derivatives with altered antibacterial profiles including anti-tubercular activity.