Structure of the molecular bushing of the bacterial flagellar motor

Nat Commun. 2021 Jul 22;12(1):4469. doi: 10.1038/s41467-021-24715-3.

Abstract

The basal body of the bacterial flagellum is a rotary motor that consists of several rings (C, MS and LP) and a rod. The LP ring acts as a bushing supporting the distal rod for its rapid and stable rotation without much friction. Here, we use electron cryomicroscopy to describe the LP ring structure around the rod, at 3.5 Å resolution, from Salmonella Typhimurium. The structure shows 26-fold rotational symmetry and intricate intersubunit interactions of each subunit with up to six partners, which explains the structural stability. The inner surface is charged both positively and negatively. Positive charges on the P ring (the part of the LP ring that is embedded within the peptidoglycan layer) presumably play important roles in its initial assembly around the rod with a negatively charged surface.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacterial Proteins / chemistry*
  • Bacterial Proteins / physiology
  • Bacterial Proteins / ultrastructure*
  • Basal Bodies / chemistry
  • Basal Bodies / physiology
  • Basal Bodies / ultrastructure
  • Cryoelectron Microscopy
  • Flagella / chemistry*
  • Flagella / physiology
  • Flagella / ultrastructure*
  • Models, Molecular
  • Molecular Motor Proteins / chemistry*
  • Molecular Motor Proteins / physiology
  • Molecular Motor Proteins / ultrastructure*
  • Movement / physiology
  • Protein Interaction Domains and Motifs
  • Protein Structure, Quaternary
  • Protein Subunits
  • Salmonella typhimurium / chemistry
  • Salmonella typhimurium / physiology
  • Salmonella typhimurium / ultrastructure
  • Static Electricity

Substances

  • Bacterial Proteins
  • Molecular Motor Proteins
  • Protein Subunits