Exploring the natural diversity of acyltransferases producing gene-encoded lipopeptides Johannes Eckert 1 , Nina M. Bösch 1 , Florian Hubrich 1 , Serina L. Robinson 2 , Anna L. Vagstad 1 , Jörn Piel 1 1 ETH Zürich, Switzerland, 2 (Eawag), Department of Environmental Microbiology, Switzerland Lipopeptides have known functions as antimicrobial and antifungal agents and have also found uses in immunotherapies and as additives in personal care products 1 . However, the production of classic lipopeptide natural products continues to be a challenge due to their non-ribosomal biosynthetic route by megasynthetases. In contrast, ribosomally synthetized and post-translationally modified peptides (RiPPs) offer a more streamlined route to peptide natural products. Their primary structure is determined by a genetically encoded precursor protein, which is modified by maturases within the same biosynthetic gene cluster 2 . A novel class of maturases of the GCN5-related N -acetyltransferase (GNAT) family was recently discovered, which introduce medium-chain fatty acids onto the sidechain amino group of lysines or arginine-derived ornithines 3 . Here we present the natural diversity of this GNAT family by characterizing the substrate scope of selected GNATs with their cognate precursor substrates. We could show that a variety of fatty acids can be introduced including chain lengths from C10 to C20 as well as desaturated and hydroxylated lipids. Each enzyme is selective for a distinct narrow set of fatty acids. Moreover, the position of the modification in the natural substrate is predetermined, even if several potential target sidechains are available. The preferred position is determined by the respective GNAT and can occur from the N-terminal position to the C-terminal position in different precursors. We are currently exploring this enzyme class to enable custom peptide engineering efforts towards generating bioactive lipopeptide compounds. References 1. Hamley, Comm. 2015 , 41, 8574-8583.Montalbán-López, et al., Prod. Rep. 2021 , 38 (1), 130-239 2. Hubrich and Bösch, et al., Natl. Acad. Sci. 2022, 119 (3)
P18
© The Author(s), 2022
Made with FlippingBook Learn more on our blog