Haloplasma MreB reconstitution in a minimal synthetic bacterium reveals orthogonal force directions underlying distinct Mollicute motility systems
- 1Osaka Metropolitan University
Abstract
MreB, a bacterial actin homolog, is widely conserved in bacteria where it functions as a scaffold for a peptidoglycan synthesis. Intriguingly, members of the cell wall-lacking Mollicutes retain multiple mreB genes despite the absence of peptidoglycan. Previous work demonstrated that two MreB isoforms from Spiroplasma can reconstitute swimming motility in the minimal synthetic bacterium syn3B, indicating that MreB was repurposed for motility. Here, we expressed seven MreBs from Haloplasma contractile, an early-diverging Mollicute, in syn3B. Approximately 50% of cells elongated, and 15% exhibited curving and coiling movements that resembled Haloplasma but differed from Spiroplasma motility. Systematic analysis of isoform combinations revealed that movement requires specific MreB pairs, and that additional isoforms enhance motility efficiency. Cryo-electron tomography showed membrane-associated ribbons composed of MreB filaments. Mathematical modeling demonstrated that Haloplasma- and Spiroplasma-type movements can be reproduced by altering only the direction of force generation. Thus, diversification of force orientation within an actin homolog enabled independent evolution of distinct motility systems in Mollicutes.
Related
- Reconstitution of the Trimethylamine Oxide Reductase Regulatory Elements of Shewanella oneidensis in Escherichia coli
- BCL10 deficiency: Long-term immune reconstitution following hematopoietic stem cell transplantation.
- Immune Reconstitution and Antigenic Exposure History Shape Virus-Specific Humoral Immunity in People with HIV
- Cell-free reconstitution reveals synergistic stabilization of microtubule doublets by PACRG and FAP20
- Reconstitution of lipid nanoparticle-mediated siRNA transfer across endosomal membrane mimics
BibTeX
@misc{mimura2026haloplasma,
title = {{Haloplasma MreB reconstitution in a minimal synthetic bacterium reveals orthogonal force directions underlying distinct Mollicute motility systems}},
author = {M. Mimura and H. Yuasa and H. Wada and H. Kiyama and Y. Kitaoku and S. Kato and Y. Sasajima and Y. O. Tahara and A. Uenoyama and T. Miyata and F. Makino and M. Ohkuma and S. Kakizawa and R. Robinson and K. Namba and M. Miyata},
howpublished = {bioRxiv},
year = {2026},
month = jun,
doi = {10.64898/2026.06.16.731841},
url = {https://www.biorxiv.org/content/10.64898/2026.06.16.731841v3},
note = {CC BY},
}
RIS
TY - UNPB
TI - Haloplasma MreB reconstitution in a minimal synthetic bacterium reveals orthogonal force directions underlying distinct Mollicute motility systems
AU - M. Mimura
AU - H. Yuasa
AU - H. Wada
AU - H. Kiyama
AU - Y. Kitaoku
AU - S. Kato
AU - Y. Sasajima
AU - Y. O. Tahara
AU - A. Uenoyama
AU - T. Miyata
AU - F. Makino
AU - M. Ohkuma
AU - S. Kakizawa
AU - R. Robinson
AU - K. Namba
AU - M. Miyata
PY - 2026
DA - 2026/06/16
PB - bioRxiv
DO - 10.64898/2026.06.16.731841
UR - https://www.biorxiv.org/content/10.64898/2026.06.16.731841v3
AB - MreB, a bacterial actin homolog, is widely conserved in bacteria where it functions as a scaffold for a peptidoglycan synthesis. Intriguingly, members of the cell wall-lacking Mollicutes retain multiple mreB genes despite the absence of peptidoglycan. Previous work demonstrated that two MreB isoforms from Spiroplasma can reconstitute swimming motility in the minimal synthetic bacterium syn3B, indicating that MreB was repurposed for motility. Here, we expressed seven MreBs from Haloplasma contractile, an early-diverging Mollicute, in syn3B. Approximately 50% of cells elongated, and 15% exhibited curving and coiling movements that resembled Haloplasma but differed from Spiroplasma motility. Systematic analysis of isoform combinations revealed that movement requires specific MreB pairs, and that additional isoforms enhance motility efficiency. Cryo-electron tomography showed membrane-associated ribbons composed of MreB filaments. Mathematical modeling demonstrated that Haloplasma- and Spiroplasma-type movements can be reproduced by altering only the direction of force generation. Thus, diversification of force orientation within an actin homolog enabled independent evolution of distinct motility systems in Mollicutes.
ER -