Journal Article

YopN and TyeA Hydrophobic Contacts Required for Regulating Ysc-Yop Type III Secretion Activity by Yersinia pseudotuberculosis

Ruuth, Kristina, Gurung, Jyoti M., Zavialov, Anton V., Amer, Ayad A. A., Forsberg, Åke, Costa, Tiago R. D., Francis, Matthew S.

2016

Overview

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.

• Publisher: Frontiers Media SA,Frontiers Media S.A
• Subject: Amino acids / Animals / Bacteria / Bacterial Outer Membrane Proteins - chemistry / Bacterial Outer Membrane Proteins - genetics / bacterial pathogenesis / Bacterial Proteins - chemistry / Bacterial Proteins - genetics / Bacterial Proteins - secretion / Biological Transport / Calcium - chemistry / Carrier Proteins - chemistry / Carrier Proteins - genetics / Cell Line / DNA, Bacterial / Eukaryotes / Gene Expression Regulation, Bacterial / Genes, Bacterial - genetics / Hydrophobic and Hydrophilic Interactions / Hydrophobicity / Macrophages - microbiology / Membrane Proteins - chemistry / Membrane Proteins - genetics / Mice / Microbiology / Microbiology in the medical area / mikrobiologi / Mikrobiologi inom det medicinska området / Models, Molecular / molecular modelling / mutagenesis / Mutagenesis, Site-Directed / Mutation / Protein Interaction Domains and Motifs / protein secretion / Protein Stability / Protein Translocation Systems / protein-protein interaction / Proteins / Pseudotuberculosis / regulation / Regulatory sequences / Sequence Analysis / Sequence Deletion / Temperature / Two-Hybrid System Techniques / Type III Secretion Systems - genetics / Type III Secretion Systems - secretion / Yersinia pseudotuberculosis - metabolism