Interplay among Pseudomonas syringae HrpR, HrpS and HrpV proteins for regulation of the type III secretion system

In this study, we analysed the organization of HrpRS and HrpV regulatory proteins and interplay between them. We identified one key residue I26 in HrpS required for repression by HrpV. Substitution of I26 in HrpS abolishes its interaction with HrpV and impairs interactions between HrpS and HrpR and the self‐association of HrpS. We show that HrpS self‐associates and can associate simultaneously with HrpR and HrpV. We now propose that HrpS has a central role in the assembly of the regulatory HrpRSV complex. Deletion analysis of HrpR and HrpS proteins showed that C‐terminal parts of HrpR and HrpS confer determinants indispensable for their self‐assembly. HrpRS transcriptional activators from Pseudomonas syringae are regulated by HrpV through specific HrpS residue I26, and HrpS acts as a key central component in the assembly of a HrpRSV regulatory hub.
Source: FEMS Microbiology Letters - Category: Microbiology Authors: Tags: Research Letter Source Type: research