Turning spherical cells into kinking helices in wall-less bacteria

In bacteria, cell shape is determined and maintained through a complex interplay between the peptidoglycan cell wall and cytoplasmic filaments made of polymerized MreB filaments. Spiroplasma species, of the Mollicutes class, challenge this general understanding because they are characterized by a helical cell shape and kink-based motility without a cell wall. This specificity is thought to rely on 5 MreB isoformsand a specific fibril protein. In this study, comninations of these 5 MreBs and the fibril from S. citri were expressed in another Mollicute, Mycoplamsa capricolum. The abundance of these proteins were compared in S.citri at different stages of growth, as well as in Mcap transformants.