@article{mbs:/content/journal/micro/10.1099/mic.0.2006/001834-0, author = "Geissler, Brett. and Shiomi, Daisuke. and Margolin, William.", title = "The ftsA* gain-of-function allele of Escherichia coli and its effects on the stability and dynamics of the Z ring", journal= "Microbiology", year = "2007", volume = "153", number = "3", pages = "814-825", doi = "https://doi.org/10.1099/mic.0.2006/001834-0", url = "https://www.microbiologyresearch.org/content/journal/micro/10.1099/mic.0.2006/001834-0", publisher = "Microbiology Society", issn = "1465-2080", type = "Journal Article", keywords = "GFP, green fluorescent protein", keywords = "Cm, chloramphenicol", keywords = "IFM, immunofluorescence microscopy", keywords = "FRAP, fluorescence recovery after photobleaching", keywords = "t½, half-time of recovery", abstract = "Formation of the FtsZ ring (Z ring) in Escherichia coli is the first step in the assembly of the divisome, a protein machine required for cell division. Although the biochemical functions of most divisome proteins are unknown, several, including ZipA, FtsA and FtsK, have overlapping roles in ensuring that the Z ring assembles at the cytoplasmic membrane, and that it is active. As shown previously, a single amino acid change in FtsA, R286W, also called FtsA*, bypasses the requirement for either ZipA or FtsK in cell division. In this study, the properties of FtsA* were investigated further, with the eventual goal of understanding the molecular mechanism behind the bypass. Compared to wild-type FtsA, the presence of FtsA* resulted in a modest but significant decrease in the mean length of cells in the population, accelerated the reassembly of Z rings, and suppressed the cell-division block caused by excessively high levels of FtsZ. These effects were not mediated by Z-ring remodelling, because FtsA* did not alter the kinetics of FtsZ turnover within the Z ring, as measured by fluorescence recovery after photobleaching. FtsA* was also unable to permit normal cell division at below normal levels of FtsZ, or after thermoinactivation of ftsZ84(ts). However, turnover of FtsA* in the ring was somewhat faster than that of wild-type FtsA, and overexpressed FtsA* did not inhibit cell division as efficiently as wild-type FtsA. Finally, FtsA* interacted more strongly with FtsZ compared with FtsA in a yeast two-hybrid system. These results suggest that FtsA* interacts with FtsZ in a markedly different way compared with FtsA.", }