title: YopN and TyeA Hydrophobic Contacts Required for Regulating Ysc-Yop Type III Secretion Activity by Yersinia pseudotuberculosis.
abstract: Yersinia bacteria target Yop effector toxins to the interior of host immune cells by the Ysc-Yop type III secretion system. A YopN-TyeA heterodimer is central to controlling Ysc-Yop targeting activity. A + 1 frameshift event in the 3-prime end of yopN can also produce a singular secreted YopN-TyeA polypeptide that retains some regulatory function even though the C-terminal coding sequence of this YopN differs greatly from wild type. Thus, this YopN C-terminal segment was analyzed for its role in type III secretion control. Bacteria producing YopN truncated after residue 278, or with altered sequence between residues 279 and 287, had lost type III secretion control and function. In contrast, YopN variants with manipulated sequence beyond residue 287 maintained full control and function. Scrutiny of the YopN-TyeA complex structure revealed that residue W279 functioned as a likely hydrophobic contact site with TyeA. Indeed, a YopN W279G mutant lost all ability to bind TyeA. The TyeA residue F8 was also critical for reciprocal YopN binding. Thus, we conclude that specific hydrophobic contacts between opposing YopN and TyeA termini establishes a complex needed for regulating Ysc-Yop activity.
authors.affiliation: Department of Molecular Biology, Umeå UniversityUmeå, Sweden; Umeå Centre for Microbial Research, Umeå UniversityUmeå, Sweden.
authors.forename: Ayad A A
authors.initials: AA
authors.lastname: Amer
authors.affiliation: Department of Molecular Biology, Umeå UniversityUmeå, Sweden; Umeå Centre for Microbial Research, Umeå UniversityUmeå, Sweden.
authors.forename: Jyoti M
authors.initials: JM
authors.lastname: Gurung
authors.affiliation: Department of Molecular Biology, Umeå UniversityUmeå, Sweden; Umeå Centre for Microbial Research, Umeå UniversityUmeå, Sweden.
authors.forename: Tiago R D
authors.initials: TR
authors.lastname: Costa
authors.affiliation: Department of Molecular Biology, Umeå UniversityUmeå, Sweden; Umeå Centre for Microbial Research, Umeå UniversityUmeå, Sweden.
authors.forename: Kristina
authors.initials: K
authors.lastname: Ruuth
authors.affiliation: Department of Molecular Biology, Uppsala BioCenter, Swedish University of Agricultural SciencesUppsala, Sweden; Joint Biotechnology Laboratory, Department of Chemistry, University of TurkuTurku, Finland.
authors.forename: Anton V
authors.initials: AV
authors.lastname: Zavialov
authors.affiliation: Department of Molecular Biology, Umeå UniversityUmeå, Sweden; Umeå Centre for Microbial Research, Umeå UniversityUmeå, Sweden; Laboratory for Molecular Infection Medicine Sweden, Umeå UniversityUmeå, Sweden.
authors.forename: Åke
authors.initials: Å
authors.lastname: Forsberg
authors.affiliation: Department of Molecular Biology, Umeå UniversityUmeå, Sweden; Umeå Centre for Microbial Research, Umeå UniversityUmeå, Sweden.
authors.forename: Matthew S
authors.initials: MS
authors.lastname: Francis
mesh_terms: D000818:Animals; D001425:Bacterial Outer Membrane Proteins / Q000737:chemistry* / Q000235:genetics; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D001692:Biological Transport; D002118:Calcium / Q000737:chemistry; D002352:Carrier Proteins / Q000737:chemistry* / Q000235:genetics; D002460:Cell Line; D004269:DNA, Bacterial; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial / Q000235:genetics; D057927:Hydrophobic and Hydrophilic Interactions; D047908:Intracellular Signaling Peptides and Proteins; D008264:Macrophages / Q000382:microbiology; D008565:Membrane Proteins / Q000737:chemistry* / Q000235:genetics; D051379:Mice; D008958:Models, Molecular; D016297:Mutagenesis, Site-Directed; D054730:Protein Interaction Domains and Motifs; D055550:Protein Stability; D000069284:Protein Translocation Systems; D017421:Sequence Analysis; D017384:Sequence Deletion; D013696:Temperature; D020798:Two-Hybrid System Techniques; D000069296:Type III Secretion Systems / Q000235:genetics / Q000378:metabolism*; D015011:Yersinia pseudotuberculosis / Q000378:metabolism*
chemical_list: D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D002352:Carrier Proteins; D004269:DNA, Bacterial; D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins; D000069284:Protein Translocation Systems; C112196:TyeA protein, Yersinia; D000069296:Type III Secretion Systems; C070015:YopN protein, Yersinia; D002118:Calcium
keywords: bacterial pathogenesis; molecular modeling; mutagenesis; protein secretion; protein-protein interaction; regulation