title: The Pseudomonas syringae pv. tomato DC3000 type III effector HopF2 has a putative myristoylation site required for its avirulence and virulence functions.
abstract: The HopPtoF locus in Pseudomonas syringae pv. tomato DC3000 harbors two genes, ShcF and HopF2 (previously named ShcF(Pto) and HopF(Pto)), that encode a type III chaperone and a cognate effector protein, respectively. The HopF2 gene has a rare initiation codon, ATA that was reported to be functional only in mitochondrial genes. Here, we report that the native HopPtoF locus of DC3000 confers an avirulence function in tobacco W38 plants, indicating that the ATA start codon directs the synthesis of a functional effector. However, disruption of HopF2 in DC3000 genome did not alter the bacterial virulence in tomato plants. The HopPtoF locus displayed a measurable virulence activity in two strains of P. syringae pv. tomato when the ATA start codon was changed to ATG, and this change also elevated the avirulence function in W38 plants. HopF2 contains a putative myristoylation site. Mutational analysis indicated that this site is required for plasma membrane localization and virulence and avirulence activities of HopF2.
authors.affiliation: Department of Plant Pathology, Kansas State University, Manhattan 66506-5502, USA.
authors.forename: Alexandre
authors.initials: A
authors.lastname: Robert-Seilaniantz
authors.forename: Libo
authors.initials: L
authors.lastname: Shan
authors.forename: Jian-Min
authors.initials: JM
authors.lastname: Zhou
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Tang
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism*; D016923:Cell Death; D002462:Cell Membrane / Q000378:metabolism; D018551:Solanum lycopersicum / Q000033:anatomy & histology / Q000382:microbiology*; D019697:Onions / Q000166:cytology; D010935:Plant Diseases / Q000382:microbiology; D018515:Plant Leaves / Q000382:microbiology; D021381:Protein Transport; D044224:Pseudomonas syringae / Q000145:classification / Q000378:metabolism* / Q000472:pathogenicity*; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D014026:Nicotiana / Q000033:anatomy & histology / Q000382:microbiology; D014774:Virulence
chemical_list: D001426:Bacterial Proteins; D011993:Recombinant Fusion Proteins