A secreted metal-binding protein protects necrotrophic phytopathogens from reactive oxygen species

• Published in: Nature communications 2019-10, Vol.10 (1), p.4853-15, Article 4853
• Main Authors: Liu, Lulu, Gueguen-Chaignon, Virginie, Gonçalves, Isabelle R, Rascle, Christine, Rigault, Martine, Dellagi, Alia, Loisel, Elise, Poussereau, Nathalie, Rodrigue, Agnès, Terradot, Laurent, Condemine, Guy
• Format: Article
• Language: English
• Subjects: 38; 38/39; 631/326/193; 631/326/41; 631/326/421; 631/92/321; 82/80; Anti-Infective Agents, Local - pharmacology; Arabidopsis - genetics; Arabidopsis - metabolism; Arabidopsis Proteins - genetics; Bacteria; Bacteriology; Biochemistry; Biochemistry, Molecular Biology; Botrytis - genetics; Botrytis - metabolism; Carrier Proteins - metabolism; Cell walls; Copper - metabolism; Crystal structure; Defensins - genetics; Dickeya; Dimerization; Dimers; Fungi; Gammaproteobacteria - drug effects; Gammaproteobacteria - genetics; Gammaproteobacteria - metabolism; Genomics; Gram-positive bacteria; Heavy metals; Homology; Humanities and Social Sciences; Hydrogen peroxide; Hydrogen Peroxide - pharmacology; Iron; Iron - metabolism; Iron-binding protein; Iron-Binding Proteins - genetics; Iron-Binding Proteins - metabolism; Life Sciences; Microbiology and Parasitology; Microorganisms; Molecular biology; Molecular structure; multidisciplinary; Plant Diseases - genetics; Plant Diseases - microbiology; Plant protection; Plants (botany); Proteins; Reactive oxygen species; Reactive Oxygen Species - metabolism; Science; Science (multidisciplinary); Siderophores - genetics; Siderophores - metabolism
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-019-12826-x

Few secreted proteins involved in plant infection common to necrotrophic bacteria, fungi and oomycetes have been identified except for plant cell wall-degrading enzymes. Here we study a family of iron-binding proteins that is present in Gram-negative and Gram-positive bacteria, fungi, oomycetes and some animals. Homolog proteins in the phytopathogenic bacterium Dickeya dadantii (IbpS) and the fungal necrotroph Botrytis cinerea (BcIbp) are involved in plant infection. IbpS is secreted, can bind iron and copper, and protects the bacteria against H 2 O 2 -induced death. Its 1.7 Å crystal structure reveals a classical Venus Fly trap fold that forms dimers in solution and in the crystal. We propose that secreted Ibp proteins binds exogenous metals and thus limit intracellular metal accumulation and ROS formation in the microorganisms. The authors identify a family of iron-binding proteins that is present in phytopathogenic bacteria, fungi and oomycetes. Some of these proteins are secreted, bind metals, protect the pathogen from H 2 O 2 -induced death, and are involved in plant infection.