Characterization of the MinD/ParA‐type ATPase FlhG in Vibrio alginolyticus and implications for function of its monomeric form. (17th February 2020)

• Record Type: Journal Article
• Authors: Kojima, Seiji; Imura, Yoshino; Hirata, Hikaru; Homma, Michio
• Is Part Of: Genes to cells. Volume 25:Number 4(2020)
• Page Start: 279
• Page End: 287
• Publication Date: 2020-02-17
• Subjects: ATP binding -- ATPase -- bacterial flagellum -- protein localization -- Vibrio; Cytogenetics -- Periodicals; Cells -- Mechanical properties -- Periodicals; Molecular genetics -- Periodicals; Genes -- Periodicals; Molecular biology -- Periodicals; Cytology -- Periodicals; Biomechanics -- Periodicals; 571.6
• DOI: 10.1111/gtc.12754
• Languages: English
• ISSNs: 1356-9597

Abstract

Abstract: FlhG is a MinD/ParA‐type ATPase that works as a negative regulator for flagellar biogenesis. In Vibrio alginolyticus, FlhG functions antagonistically with the positive regulator FlhF to generate a single polar flagellum. Here, we examined the effects of ADP and ATP on the aggregation and dimerization of Vibrio FlhG. Purified FlhG aggregated after exposure to low NaCl conditions, and its aggregation was suppressed in the presence of ADP or ATP. FlhG mutants at putative ATP‐binding (K31A) or catalytic (D60A) residues showed similar aggregation profiles to the wild type, but ATP caused strong aggregation of the ATPase‐stimulated D171A mutant although ADP significantly suppressed the aggregation. Results of size exclusion chromatography of purified FlhG or Vibrio cell lysates suggested that FlhG exists as a monomer in solution, and ATP does not induce FlhG dimerization. The K31A and D60A mutants eluted at monomer fractions regardless of nucleotides, but ATP shifted the elution peak of the D171A mutant to slightly earlier, presumably because of a subtle conformational change. Our results suggest that monomeric FlhG can function in vivo, whose active conformation aggregates easily. Abstract : FlhG is a MinD/ParA‐type ATPase that is a negative regulator of flagellar biogenesis. The aggregation of FlhG is suppressed by ADP or ATP, and ATP seems not to induce dimerization in contrast to MinD. Results raise a possibility that monomeric FlhG can function in vivo, whose active conformation aggregates easily.