The Longitudinal Dividing Bacterium Candidatus Thiosymbion Oneisti Has a Natural Temperature-Sensitive FtsZ Protein with Low GTPase Activity

FtsZ, the bacterial tubulin-homolog, plays a central role in cell division and polymerizes into a ring-like structure at midcell to coordinate other cell division proteins. The rod-shaped gamma-proteobacterium Candidatus Thiosymbion oneisti has a medial discontinuous ellipsoidal Z-ring. Ca. T. oneisti FtsZ shows temperature-sensitive characteristics when it is expressed in Escherichia coli, where it localizes at midcell. The overexpression of Ca. T. oneisti FtsZ interferes with cell division and results in filamentous cells. In addition, it forms ring- and barrel-like structures independently of E. coli FtsZ, which suggests that the difference in shape and size of the Ca. T. oneisti FtsZ ring is likely the result of its interaction with Z-ring organizing proteins. Similar to some temperature-sensitive alleles of E. coli FtsZ, Ca. T. oneisti FtsZ has a weak GTPase and does not polymerize in vitro. The temperature sensitivity of Ca. Thiosymbion oneisti FtsZ is likely an adaptation to the preferred temperature of less than 30 degrees C of its host, the nematode Laxus oneistus.

Automated summary

FtsZ, a bacterial tubulin-homolog, plays a central role in cell division and forms a ring-like structure. Candidatus Thiosymbion oneisti FtsZ shows temperature-sensitive characteristics and has a different shape, which is likely due to its interaction with Z-ring organizing proteins. The temperature sensitivity of Ca. Thiosymbion oneisti FtsZ is an adaptation to the preferred temperature of its host, the nematode Laxus oneistus.