Interaction of unphosphorylated PtsN with the K⁺/H⁺ antiporter YcgO inhibits its activity in Escherichia coli.

ABSTRACT: Genetic studies in Escherichia coli have implicated the unphosphorylated version of PtsN (unphospho-PtsN), the terminal phospho-acceptor of the PtsP-PtsO-PtsN phosphorelay, as a negative regulator of potassium (K⁺) efflux mediated by YcgO. YcgO is a protein belonging to the CPA1 family of monovalent cation/proton antiporters. Here we show that in vivo, YcgO comprises an approximately 383 amino acid N-terminal transmembrane domain and a 195 amino acid C-terminal cytoplasmic region (CTR). Copurification studies show that unphospho-PtsN specifically interacts with YcgO, and phosphorylation of PtsN leads to marked attenuation of the interaction. Genetic and biochemical analyses of a class of mutations in YcgO that lead to constitutive activation of YcgO identify the CTR as the site

SUBMITTER: Patidar Y 

PROVIDER: S-EPMC11808508 | biostudies-literature | 2025 Feb

REPOSITORIES: biostudies-literature