2
views
0
recommends
+1 Recommend
0 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: not found

      Using disruptive insertional mutagenesis to identify the in situ structure‐function landscape of the Shigella translocator protein IpaB

      research-article

      Read this article at

      ScienceOpenPublisherPMC
      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          Bacterial type III secretion systems (T3SS) are used to inject proteins into mammalian cells to subvert cellular functions. The Shigella T3SS apparatus (T3SA) is comprised of a basal body, cytoplasmic sorting platform and exposed needle with needle “tip complex” (TC). TC maturation occurs when the translocator protein IpaB is recruited to the needle tip where both IpaD and IpaB control secretion induction. IpaB insertion into the host membrane is the first step of translocon pore formation and secretion induction. We employed disruptive insertional mutagenesis, using bacteriophage T4 lysozyme (T4L), within predicted IpaB loops to show how topological features affect TC functions (secretion control, translocon formation and effector secretion). Insertions within the N‐terminal half of IpaB were most likely to result in a loss of steady‐state secretion control, however, all but the two that were not recognized by the T3SA retained nearly wild‐type hemolysis (translocon formation) and invasiveness levels (effector secretion). In contrast, all but one insertion in the C‐terminal half of IpaB maintained secretion control but were impaired for hemolysis and invasion. These nature of the data suggest the latter mutants are defective in a post‐secretion event, most likely due to impaired interactions with the second translocator protein IpaC. Intriguingly, only two insertion mutants displayed readily detectable T4L on the bacterial surface. The data create a picture in which the makeup and structure of a functional T3SA TC is highly amenable to physical perturbation, indicating that the tertiary structure of IpaB within the TC is more plastic than previously realized.

          Related collections

          Author and article information

          Contributors
          picking@ku.edu
          Journal
          Protein Sci
          Protein Sci
          10.1002/(ISSN)1469-896X
          PRO
          Protein Science : A Publication of the Protein Society
          John Wiley and Sons Inc. (Hoboken )
          0961-8368
          1469-896X
          03 May 2018
          August 2018
          : 27
          : 8 ( doiID: 10.1002/pro.v27.8 )
          : 1392-1406
          Affiliations
          [ 1 ] Higuchi Biosciences Center, University of Kansas Lawrence Kansas 66047
          [ 2 ] Department of Molecular Biosciences University of Kansas Lawrence Kansas 66045
          [ 3 ] Department of Biochemistry and Molecular Biophysics Kansas State University Manhattan Kansas 66506
          [ 4 ] Protein Structure Laboratory Del Shankel Structural Biology Center, University of Kansas Lawrence KS 66045
          [ 5 ] IMCA‐CAT, Hauptman‐Woodward Medical Research Institute Argonne Illinois 60439
          [ 6 ] Department of Pharmaceutical Chemistry University of Kansas Lawrence Kansas 66047
          Author notes
          [*] [* ]Correspondence to: [William D. Picking; Department of Pharmaceutical Chemistry, University of Kansas, 320B MRB, 2030 Becker Drive, Lawrence, KS 66047]. E‐mail: picking@ 123456ku.edu
          Author information
          http://orcid.org/0000-0001-5635-325X
          Article
          PMC6153406 PMC6153406 6153406 PRO3428
          10.1002/pro.3428
          6153406
          29672980
          80396dfb-d0b3-4a6c-8c9e-e90629c24945
          © 2018 The Protein Society
          History
          : 05 March 2018
          : 12 April 2018
          : 16 April 2018
          Page count
          Figures: 7, Tables: 2, Pages: 15, Words: 11038
          Funding
          Funded by: National Institutes of Health
          Award ID: GM110761
          Award ID: AI099489
          Award ID: AI123351
          Categories
          Full‐Length Papers
          Full‐Length Papers
          Custom metadata
          2.0
          pro3428
          August 2018
          Converter:WILEY_ML3GV2_TO_NLMPMC version:version=5.4.9 mode:remove_FC converted:25.09.2018

          translocon,IpaB,type III secretion, Shigella
          translocon, IpaB, type III secretion, Shigella

          Comments

          Comment on this article