The Yersinia pseudotuberculosis degradosome is required for oxidative stress, while its PNPase subunit plays a degradosome-independent role in cold growth

Authors

  • Amanda Henry,

    1. Department of Biology, Center for Bionanotechnology and Environmental Research (CBER), Texas Southern University, Houston, TX, USA
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  • Justin Shanks,

    1. Department of Biology, Center for Bionanotechnology and Environmental Research (CBER), Texas Southern University, Houston, TX, USA
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  • Ambro van Hoof,

    1. Department of Microbiology & Molecular Genetics, The University of Texas Graduate School of Miomedical Sciences, University of Texas Health Science Center, Houston, TX, USA
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  • Jason A. Rosenzweig

    Corresponding author
    • Department of Biology, Center for Bionanotechnology and Environmental Research (CBER), Texas Southern University, Houston, TX, USA
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Correspondence: Jason A. Rosenzweig, Department of Biology, Center for Bionanotechnology and Environmental Research (CBER), Texas Southern University, 3100 Cleburne Street, Houston, TX, USA. Tel.: +1 713 313 1033; fax: +1 713 313 7932; e-mail: rosenzweigja@tsu.edu

Abstract

Yersinia polynucleotide phosphorylase (PNPase), a 3′–5′ exoribonuclease, has been shown to affect growth during several stress responses. In Escherichia coli, PNPase is one of the subunits of a multiprotein complex known as the degradosome, but also has degradosome-independent functions. The carboxy-terminus of E. coli ribonuclease E (RNase E) serves as the scaffold upon which PNPase, enolase (a glycolytic enzyme), and RhlB helicase all have been shown to bind. In the yersiniae, only PNPase has thus far been shown to physically interact with RNase E. We show by bacterial two-hybrid and co-immunoprecipitation assays that RhlB and enolase also interact with RNase E. Interestingly, although PNPase is required for normal growth at cold temperatures, assembly of the yersiniae degradosome was not required. However, degradosome assembly was required for growth in the presence of reactive oxygen species. These data suggest that while the Yersinia pseudotuberculosis PNPase plays a role in the oxidative stress response through a degradosome-dependent mechanism, PNPase's role during cold stress is degradosome-independent.

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