FtsL, an Essential Cytoplasmic Membrane Protein Involved in Cell Division in Escherichia coli

Abstract

We have identified a gene involved in bacterial cell division, located immediately upstream of theftsI gene in the min 2 region of the Escherichia coli chromosome. This gene, which we namedftsL, was detected through characterization of TnphoA insertions in a plasmid containing this chromosomal region. TnphoA topological analysis and fractionation of alkaline phosphatase fusion proteins indicated that the jtsL gene product is a 13.6-kDa cytoplasmic membrane protein with a cytoplasmic amino terminus, a single membrane-spanning segmient, and a periplasmic carboxy terminus. TheftsL gene is essential for cell growth and division. A null mutation in ftsL resulted in inhibition of cell division, formation of long, nonseptate filaments, ultimate cessation of growth, and lysis. Under certain growth conditions, depletion of FtsL or expression of the largest ftsL-phoA fusion produced a variety of cell morphologies, including Y-shaped bacteria, indicating a possible general weakening of the cell wall. The FtsL protein is estimated to be present at about 20 to 40 copies per cell. The periplasmic domain of the protein displays a sequence with features characteristic of leucine zippers, which are involved in protein dimerization.

A novel regulatory mechanism couples deoxyribonucleotide synthesis and DNA replication in Escherichia coli

“…The bacterial strains and plasmids used in this study are listed in Table I. Strains were grown routinely in NZ medium (Guzman et al , 1992) or AB glucose‐CAA medium (Bach and Skarstad, 2004) at 37°C. For growth of MG1655 strains, 100 μg/ml uridine was added.…”

The Pneumococcal Divisome: Dynamic Control of Streptococcus pneumoniae Cell Division

“…Given that the homologous protease RseP from E. coli uses zinc as a co-factor ( Hizukuri et al, 2017 ), it is possible that zinc availability may be an important and unexplored regulator of this stage of pneumococcal cell division. FtsL is essential in E. coli and is thought to play a role in zinc sensitivity and by extension, membrane permeability ( Guzman et al, 1992 ; Blencowe et al, 2011 ). Although the role of pneumococcal FtsL is unknown, the conservation of this complex across all bacteria makes it likely that FtsL’s function is also conserved.…”