FtsZ-Dependent Elongation of a Coccoid Bacterium

• Main Authors: Ana R. Pereira, Jen Hsin, Ewa Król, Andreia C. Tavares, Pierre Flores, Egbert Hoiczyk, Natalie Ng, Alex Dajkovic, Yves V. Brun, Michael S. VanNieuwenhze, Terry Roemer, Rut Carballido-Lopez, Dirk-Jan Scheffers, Kerwyn Casey Huang, Mariana G. Pinho
• Format: Article
• Language: English
• Published: American Society for Microbiology 2016-09-01
• Series: mBio
• Online Access: http://mbio.asm.org/cgi/content/full/7/5/e00908-16

A mechanistic understanding of the determination and maintenance of the simplest bacterial cell shape, a sphere, remains elusive compared with that of more complex shapes. Cocci seem to lack a dedicated elongation machinery, and a spherical shape has been considered an evolutionary dead-end morphology, as a transition from a spherical to a rod-like shape has never been observed in bacteria. Here we show that a Staphylococcus aureus mutant (M5) expressing the ftsZG193D allele exhibits elongated cells. Molecular dynamics simulations and in vitro studies indicate that FtsZG193D filaments are more twisted and shorter than wild-type filaments. In vivo, M5 cell wall deposition is initiated asymmetrically, only on one side of the cell, and progresses into a helical pattern rather than into a constricting ring as in wild-type cells. This helical pattern of wall insertion leads to elongation, as in rod-shaped cells. Thus, structural flexibility of FtsZ filaments can result in an FtsZ-dependent mechanism for generating elongated cells from cocci.