title: The mode of action of the plant antimicrobial peptide MiAMP1 differs from that of its structural homologue, the yeast killer toxin WmKT.
abstract: The plant antimicrobial peptide MiAMP1 from Macadamia integrifolia and the yeast killer toxin peptide WmKT from Williopsis mrakii are structural homologues. Comparative studies of yeast mutants were performed to test their sensitivity to these two antimicrobial peptides. No differences in susceptibility to MiAMP1 were detected between wild-type and several WmKT-resistant mutant yeast strains. A yeast mutant MT1, resistant to MiAMP1 but unaffected in its susceptibility to plant defensins and hydrogen peroxide, also did not show enhanced tolerance towards WmKT. It is therefore probable that the Greek key beta-barrel structure shared by MiAMP1 and WmKT provides a robust structural framework ensuring stability for the two proteins but that the specific action of the peptides depends on other motifs.
authors.affiliation: Cooperative Research Centre for Tropical Plant Protection, University of Queensland, Brisbane, Qld 4072, Australia. camilla.stephens@uq.edu.au
authors.forename: Camilla
authors.initials: C
authors.lastname: Stephens
authors.forename: Kemal
authors.initials: K
authors.lastname: Kazan
authors.forename: Ken C
authors.initials: KC
authors.lastname: Goulter
authors.forename: Donald J
authors.initials: DJ
authors.lastname: Maclean
authors.forename: John M
authors.initials: JM
authors.lastname: Manners
mesh_terms: D025141:Drug Resistance, Fungal; D055646:Killer Factors, Yeast; D039106:Macadamia / Q000235:genetics / Q000378:metabolism; D008826:Microbial Sensitivity Tests; D009154:Mutation; D009183:Mycotoxins / Q000737:chemistry / Q000494:pharmacology*; D010455:Peptides / Q000737:chemistry / Q000494:pharmacology; D010940:Plant Proteins / Q000737:chemistry / Q000494:pharmacology*; D012441:Saccharomyces cerevisiae / Q000187:drug effects* / Q000235:genetics / Q000254:growth & development; D029701:Saccharomyces cerevisiae Proteins; D004718:Saccharomycetales / Q000235:genetics / Q000378:metabolism
chemical_list: C105617:AMP1 protein, Macadamia integrifolia; C527157:KHR1 protein, S cerevisiae; D055646:Killer Factors, Yeast; D009183:Mycotoxins; D010455:Peptides; D010940:Plant Proteins; D029701:Saccharomyces cerevisiae Proteins