In the current model for bacterial cell division, FtsZ protein forms a ring that marks division plane, creating cytoskeletal framework subsequent action of other proteins such as FtsA. This putative complex ultimately generates septum. Herein we report and FtsA tagged with green fluorescent (GFP) colocalize to division-site ring-like structures in living cells visible space between segregated nucleoids. Cells higher levels FtsZ–GFP or FtsA–GFP plus excess wild-type were inhibited often...

Adsorption and genome ejection are fundamental to the bacteriophage life cycle, yet their molecular mechanisms not well understood. We used cryo-electron tomography capture T7 virions at successive stages of infection Escherichia coli minicells ~4-nm resolution. The six phage tail fibers were folded against capsid, extending orienting symmetrically only after productive adsorption host cell surface. Receptor binding by triggered conformational changes resulting in insertion an extended tail,...

Bacteria have evolved multiple strategies to sense and rapidly adapt challenging ever-changing environmental conditions. The ability alter membrane lipid composition, a key component of the cellular envelope, is crucial for bacterial survival adaptation in response stress. However, precise roles played by phospholipids physiology stress are not fully elucidated. goal this study was define role maintenance cell fitness. By using genetically modified strains which phospholipid composition can...

Bacterial type III secretion machines are widely used to inject virulence proteins into eukaryotic host cells. These evolutionarily related bacterial flagella and consist of a large cytoplasmic complex, transmembrane basal body, an extracellular needle. The complex forms sorting platform essential for effector selection needle assembly, but it remains largely uncharacterized. Here we use high-throughput cryoelectron tomography (cryo-ET) visualize intact in virulent Shigella flexneri strain...

Significance The bacteriophage T4 tail is a complex nanomachine that undergoes succession of structural changes as it infects bacterium. We analyzed cryo-electron microscopic images at different stages infection. Three-dimensional visualization key intermediates revealed unprecedented details, allowing better understanding this fundamental and highly efficient process. Contrary to common descriptions, most long fibers are folded back against the virion before infection, not all interact with...

To understand further the role of nucleoid and min system in selection cell division site, we examined FtsZ localization Escherichia coli cells lacking MinCDE parC mutants defective chromosome segregation. More than one ring was sometimes found gaps between nucleoids mutant filaments. These multiple rings were more apparent longer cells; double or triple often nucleoid-free ftsI ftsA Introducing a mutation into allowed to become significantly longer. contained dramatic clusters rings. In...

ABSTRACT In Escherichia coli , FtsZ is required for the recruitment of essential cell division proteins FtsA and ZipA to septal ring. Several C-terminal deletions E. FtsZ, including one only 12 amino acids that removes highly conserved core domain, failed complement chromosomal ftsZ mutants when expressed on a plasmid. To identify key individual residues within six were replaced with alanines. All but these (D373A) an mutant. Immunoblot analysis demonstrated whereas I374A F377A unstable in...

ZipA and FtsA are recruited independently to the FtsZ cytokinetic ring (Z ring) essential for cell division of Escherichia coli . The molecular role in is unknown; however, thought stabilize Z ring, anchor it membrane, recruit downstream proteins. Here we demonstrate that requirement can be bypassed completely by a single alteration conserved residue (FtsA*). Cells with ftsA * copy place WT or alone on multicopy plasmid divide mostly normally, whether they zipA + −. Experiments ftsQAZ ftsQA...

The dynamics and assembly of bacterial cell division protein FtsZ were monitored in individual, growing dividing Escherichia coli cells real time by microculture a merodiploid strain expressing green fluorescent (GFP)-tagged FtsZ. Cells FtsZ-GFP at levels less than or equivalent to that wild-type able grow divide over multiple generations, with their rings visualized fluorescence. During the late stages cytokinesis, which constituted last one-fourth cycle, lumen ring disappeared as whole...

The chemoreceptors of Escherichia coli localize to the cell poles and form a highly ordered array in concert with CheA kinase CheW coupling factor. However, high-resolution structure has been lacking, molecular basis assembly thus remained elusive. Here, we use cryoelectron tomography flagellated E. minicells derive 3D map intact array. Docking structures into provides model core signaling complex, which CheA/CheW dimer bridges two adjacent receptor trimers via multiple hydrophobic...

The actinomycete Corynebacterium glutamicum grows as rod-shaped cells by zonal peptidoglycan synthesis at the cell poles. In this bacterium, experimental depletion of polar DivIVA protein (DivIVA(Cg)) resulted in inhibition growth; consequently, these exhibited a coccoid morphology. This result demonstrated that is required for elongation and acquisition rod shape. from Streptomyces or Mycobacterium localized to poles DivIVA(Cg)-depleted C. restored synthesis, contrast proteins Bacillus...

ABSTRACT Assembly of the cell division apparatus in bacteria starts with formation Z ring on cytoplasmic face membrane. This process involves accumulation FtsZ polymers at midcell and their interaction several FtsZ-binding proteins that collectively organize into a membrane-associated ring-like configuration. Three such proteins, FtsA, ZipA, ZapA, have previously been identified Escherichia coli . FtsA ZipA are essential help connect inner ZapA is protein not required for fission per se but...

Background/objectives: FtsZ, a eukaryotic tubulin homolog and an essential component of the bacterial divisome, is target numerous antimicrobial compounds as well proteins peptides, most which inhibit FtsZ polymerization dynamics. We previously showed that Kil peptide from bacteriophage λ inhibits Escherichia coli cell division by disrupting ring assembly, this inhibition requires presence membrane anchor protein ZipA. Methods: To investigate Kil's molecular mechanism further, we employed...