9LJL

Structure of the periplasmic domain of MotS from Bacillus subtilis in 300 mM NaCl

Summary for 9LJL

• Entry DOI: 10.2210/pdb9ljl/pdb
• Related: 9LJK
• Descriptor: Flagellar motor protein MotS (2 entities in total)
• Functional Keywords: bacterial flagellum, stator protein, peptidoglycan binding, motor protein
• Biological source: Bacillus subtilis
• Total number of polymer chains: 2
• Total formula weight: 41805.34

Authors

Yamaguchi, A.,Takekawa, N.,Imada, K. (deposition date: 2025-01-15, release date: 2025-02-26, Last modification date: 2025-03-19)

Primary citation

Takekawa, N.,Yamaguchi, A.,Nishiuchi, K.,Uehori, M.,Kinoshita, M.,Minamino, T.,Imada, K.
Sodium-Dependent Conformational Change in Flagellar Stator Protein MotS from Bacillus subtilis.
Biomolecules, 15:-, 2025

PubMed Abstract: The bacterial flagellar motor consists of a rotor and stator units and is driven by ion flow through the stator. The activation of the ion flow is coupled with the anchoring of the stator units to the peptidoglycan layer by the stator B-subunit around the rotor. Gram-negative bacteria, such as and , change the conformation of the N-terminal helix of the periplasmic domain of the B-subunit to anchor the stator units. However, a recent high-speed atomic force microscopic study has suggested that the periplasmic domain of MotS, the stator B-subunit of the sodium (Na)-driven stator of , a gram-positive bacterium, unfolds at low external Na concentrations and folds at high Na concentrations to anchor the stator units. Here, we report the crystal structures of MotS, a periplasmic fragment of MotS, from at high and low Na concentrations. We also performed far-UV CD spectroscopic analysis of the wild-type MotS and MotS proteins and mutant variants of MotS under high and low Na concentrations and found that the N-terminal disordered region of MotS shows a Na-dependent coil-helix transition. We propose a mechanism of the Na-dependent structural transition of Bs-MotS to anchor the stator units.

PubMed: 40001605
DOI: 10.3390/biom15020302

Experimental method

X-RAY DIFFRACTION (1.89 Å)