biostudies-literatureKessler SCAustralian Research Council24243-24250https://www.ebi.ac.uk/biostudies/studies/S-EPMC7533671biostudies-literatureUnknown117(39)The necrotrophic fungal pathogen <i>Cochliobolus victoriae</i> produces victorin, a host-selective toxin (HST) essential for pathogenicity to certain oat cultivars with resistance against crown rust. Victorin is a mixture of highly modified heterodetic cyclic hexapeptides, previously assumed to be synthesized by a nonribosomal peptide synthetase. Herein, we demonstrate that victorin is a member of the ribosomally synthesized and posttranslationally modified peptide (RiPP) family of natural products. Analysis of a newly generated long-read assembly of the <i>C. victoriae</i> genome revealed three copies of precursor peptide genes (<i>vicA1-3</i>) with variable numbers of "GLKLAF" core peptide repeats corresponding to the victorin peptide backbone. <i>vicA1-3</i> are located in repeat-rich gProceedings of the National Academy of Sciences of the United States of AmericaVictorin, the host-selective cyclic peptide toxin from the oat pathogen <i>Cochliobolus victoriae</i>, is ribosomally encoded.PMC7533671FT160100233DP210102180DP200101880Chooi YHKessler SCZhang XTurgeon BGMcDonald MCRightmyer ALin ZSolomon PSGilchrist CLMfalseVictorin, the host-selective cyclic peptide toxin from the oat pathogen <i>Cochliobolus victoriae</i>, is ribosomally encoded.The necrotrophic fungal pathogen <i>Cochliobolus victoriae</i> produces victorin, a host-selective toxin (HST) essential for pathogenicity to certain oat cultivars with resistance against crown rust. Victorin is a mixture of highly modified heterodetic cyclic hexapeptides, previously assumed to be synthesized by a nonribosomal peptide synthetase. Herein, we demonstrate that victorin is a member of the ribosomally synthesized and posttranslationally modified peptide (RiPP) family of natural products. Analysis of a newly generated long-read assembly of the <i>C. victoriae</i> genome revealed three copies of precursor peptide genes (<i>vicA1-3</i>) with variable numbers of "GLKLAF" core peptide repeats corresponding to the victorin peptide backbone. <i>vicA1-3</i> are located in repeat-rich g2020-01-01T00:00:00Z2020 Sep2026-05-07T15:39:39.289Z2021-03-16T08:13:05ZS-EPMC75336713292903710.1073/pnas.2010573117