The twin arginine protein transport pathway exports multiple virulence proteins in the plant pathogen Streptomyces scabies

Madhumita V. Joshi, Stefan G. Mann, Haike Antelmann, David A. Widdick, Joanna K. Fyans, Govind Chandra, Matthew I. Hutchings, Ian Toth, Michael Hecker, Rosemary Loria, Tracy Palmer (Lead / Corresponding author)

    Research output: Contribution to journalArticlepeer-review

    47 Citations (Scopus)

    Abstract

    P>Streptomyces scabies is one of a group of organisms that causes the economically important disease potato scab. Analysis of the S. scabies genome sequence indicates that it is likely to secrete many proteins via the twin arginine protein transport (Tat) pathway, including several proteins whose coding sequences may have been acquired through horizontal gene transfer and share a common ancestor with proteins in other plant pathogens. Inactivation of the S. scabies Tat pathway resulted in pleiotropic phenotypes including slower growth rate and increased permeability of the cell envelope. Comparison of the extracellular proteome of the wild type and Delta tatC strains identified 73 predicted secretory proteins that were present in reduced amounts in the tatC mutant strain, and 47 Tat substrates were verified using a Tat reporter assay. The Delta tatC strain was almost completely avirulent on Arabidopsis seedlings and was delayed in attaching to the root tip relative to the wild-type strain. Genes encoding 14 candidate Tat substrates were individually inactivated, and seven of these mutants were reduced in virulence compared with the wild-type strain. We conclude that the Tat pathway secretes multiple proteins that are required for full virulence.

    The definitive version is available at http://dx.doi.org/10.1111/j.1365-2958.2010.07206.x

    Original languageEnglish
    Pages (from-to)252-271
    Number of pages20
    JournalMolecular Microbiology
    Volume77
    Issue number1
    DOIs
    Publication statusPublished - Jul 2010

    Keywords

    • SEC-INDEPENDENT PROTEIN
    • COFACTOR-CONTAINING PROTEINS
    • TAT SIGNAL PEPTIDES
    • TRANSLOCATION PATHWAY
    • ESCHERICHIA-COLI
    • PSEUDOMONAS-SYRINGAE
    • THAXTOMIN BIOSYNTHESIS
    • COELICOLOR A3(2)
    • SECRETION
    • SYSTEM

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