FtsA G50E Mutant Suppresses the Essential Requirement for FtsK During Bacterial Cell Division in Escherichia coli

Can J Microbiol. 2020 Apr;66(4):313-327. doi: 10.1139/cjm-2019-0493. Epub 2020 Jan 23.

Abstract

In Escherichia coli, the N-terminal domain of the essential protein FtsK (FtsKN) is proposed to modulate septum formation through the formation of dynamic and essential protein interactions with both the Z-ring and late-stage division machinery. Using genomic mutagenesis, complementation analysis, and in vitro pull-down assays, we aimed to identify protein interaction partners of FtsK essential to its function during division. Here, we identified the cytoplasmic Z-ring membrane anchoring protein FtsA as a direct protein-protein interaction partner of FtsK. Random genomic mutagenesis of an ftsK temperature-sensitive strain of E. coli revealed an FtsA point mutation (G50E) that is able to fully restore normal cell growth and morphology, and further targeted site-directed mutagenesis of FtsA revealed several other point mutations capable of fully suppressing the essential requirement for functional FtsK. Together, this provides insight into a potential novel co-complex formed between these components during division and suggests FtsA may directly impact FtsK function.

Keywords: Escherichia coli; FtsA; FtsK; cell division; chemical mutagenesis; division cellulaire; interactions protéine–protéine; mutagenèse chimique; protein–protein interactions.

MeSH terms

  • Cell Division*
  • Escherichia coli / cytology
  • Escherichia coli / genetics
  • Escherichia coli / metabolism*
  • Escherichia coli Proteins / genetics
  • Escherichia coli Proteins / metabolism*
  • Gene Expression Regulation, Bacterial
  • Membrane Proteins / genetics
  • Membrane Proteins / metabolism*
  • Mutagenesis
  • Mutation, Missense
  • Protein Binding

Substances

  • Escherichia coli Proteins
  • FtsA protein, E coli
  • FtsK protein, E coli
  • Membrane Proteins