The coiled-coil domain of E. coli FtsLB is a structurally detuned element critical for modulating its activation in bacterial cell division

In 1993, William Donachie wrote “The success of molecular genetics in the study of bacterial cell division has been so great that we find ourselves, armed with much greater knowledge of detail, confronted once again with the same naive questions that we set to answer in the first place”1. Indeed, attempts to answer the apparently simple question of how a bacterial cell divides have led to a wealth of new knowledge, in particular over the past decade and a half. And while some questions have been answered to a great extent since the early reports of isolation of division mutants of Escherichia coli2,3, some key pieces of the puzzle remain elusive. In addition to it being a fundamental process in bacteria that merits investigation in its own right, studying the process of cell division offers an abundance of new targets for the development of new antibacterial compounds that act directly against key division proteins and other components of the cytoskeleton, which are encoded by the morphogenes of E. coli4. This review aims to present the reader with a snapshot summary of the key players in E. coli morphogenesis with emphasis on cell division and the rod to sphere transition.

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Assembly of bacterial cell division protein FtsZ into dynamic biomolecular condensates

10.1101/2020.08.27.271288 ◽

2020 ◽

Author(s):

Miguel Ángel Robles-Ramos ◽

Silvia Zorrilla ◽

Carlos Alfonso ◽

William Margolin ◽

Germán Rivas ◽

...

Keyword(s):

Cell Division ◽

Bacterial Cell ◽

Bound State ◽

Bacterial Cell Division ◽

Structural Element ◽

Physiological Factors ◽

General Role ◽

E Coli ◽

Division Site ◽

Synthetic Cell

Biomolecular condensation through phase separation may be a novel mechanism to regulate bacterial processes, including cell division. Previous work revealed FtsZ, a protein essential for cytokinesis in most bacteria, and the E. coli division site selection factor SlmA form FtsZ∙SlmA biomolecular condensates. The absence of condensates composed solely of FtsZ under the conditions used in that study suggested this mechanism was restricted to nucleoid occlusion or SlmA-containing bacteria. Here we report that FtsZ alone can demix into condensates in bulk and when encapsulated in synthetic cell-like systems. Condensate assembly depends on FtsZ being in the GDP-bound state and on crowding conditions that promote its oligomerization. FtsZ condensates are dynamic and gradually convert into FtsZ filaments upon GTP addition. Notably, FtsZ lacking its C-terminal disordered region, a structural element likely to favor biomolecular condensation, also forms condensates, albeit less efficiently. The inherent tendency of FtsZ to form condensates susceptible to modulation by physiological factors, including binding partners, suggests that such mechanisms may play a more general role in bacterial cell division than initially envisioned.

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Localization, Assembly, and Activation of the Escherichia coli Cell Division Machinery

EcoSal Plus ◽

10.1128/ecosalplus.esp-0022-2021 ◽

2021 ◽

Author(s):

Petra Anne Levin ◽

Anuradha Janakiraman

Keyword(s):

Escherichia Coli ◽

Cell Division ◽

Bacterial Cell ◽

Coli Cell ◽

Bacterial Cell Division ◽

Content Type ◽

E Coli ◽

Insight Into

Decades of research, much of it in Escherichia coli , have yielded a wealth of insight into bacterial cell division. Here, we provide an overview of the E. coli division machinery with an emphasis on recent findings.

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Structure and Mutational Analyses of Escherichia coli ZapD Reveal Charged Residues Involved in FtsZ Filament Bundling

Journal of Bacteriology ◽

10.1128/jb.00969-15 ◽

2016 ◽

Vol 198 (11) ◽

pp. 1683-1693 ◽

Cited By ~ 8

Author(s):

Elyse J. Roach ◽

Charles Wroblewski ◽

Laura Seidel ◽

Alison M. Berezuk ◽

Dyanne Brewer ◽

...

Keyword(s):

Escherichia Coli ◽

Cell Division ◽

Bacterial Cell ◽

Site Directed Mutagenesis ◽

Bacterial Cell Division ◽

Wild Type ◽

Content Type ◽

E Coli ◽

Z Ring

ABSTRACTBacterial cell division is an essential and highly coordinated process. It requires the polymerization of the tubulin homologue FtsZ to form a dynamic ring (Z-ring) at midcell. Z-ring formation relies on a group of FtsZ-associatedproteins (Zap) for stability throughout the process of division. InEscherichia coli, there are currently five Zap proteins (ZapA through ZapE), of which four (ZapA, ZapB, ZapC, and ZapD) are small soluble proteins that act to bind and bundle FtsZ filaments. In particular, ZapD forms a functional dimer and interacts with the C-terminal tail of FtsZ, but little is known about its structure and mechanism of action. Here, we present the crystal structure ofEscherichia coliZapD and show it forms a symmetrical dimer with centrally located α-helices flanked by β-sheet domains. Based on the structure of ZapD and its chemical cross-linking to FtsZ, we targeted nine charged ZapD residues for modification by site-directed mutagenesis. Usingin vitroFtsZ sedimentation assays, we show that residues R56, R221, and R225 are important for bundling FtsZ filaments, while transmission electron microscopy revealed that altering these residues results in different FtsZ bundle morphology compared to those of filaments bundled with wild-type ZapD. ZapD residue R116 also showed altered FtsZ bundle morphology but levels of FtsZ bundling similar to that of wild-type ZapD. Together, these results reveal that ZapD residues R116, R221, and R225 likely participate in forming a positively charged binding pocket that is critical for bundling FtsZ filaments.IMPORTANCEZ-ring assembly underpins the formation of the essential cell division complex known as the divisome and is required for recruitment of downstream cell division proteins. ZapD is one of several proteins inE. colithat associates with the Z-ring to promote FtsZ bundling and aids in the overall fitness of the division process. In the present study, we describe the dimeric structure ofE. coliZapD and identify residues that are critical for FtsZ bundling. Together, these results advance our understanding about the formation and dynamics of the Z-ring prior to bacterial cell division.

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Unite to divide: Oligomerization of tubulin and actin homologs regulates initiation of bacterial cell division

F1000Research ◽

10.12688/f1000research.13504.1 ◽

2018 ◽

Vol 7 ◽

pp. 235 ◽

Cited By ~ 15

Author(s):

Marcin Krupka ◽

William Margolin

Keyword(s):

Escherichia Coli ◽

Cell Division ◽

Bacterial Cell ◽

Cytoplasmic Membrane ◽

Bacterial Cell Division ◽

Oligomeric State ◽

Protein Association ◽

E Coli ◽

Recent Advances ◽

Initial Stage

To generate two cells from one, bacteria such asEscherichia coliuse a complex of membrane-embedded proteins called the divisome that synthesize the division septum. The initial stage of cytokinesis requires a tubulin homolog, FtsZ, which forms polymers that treadmill around the cell circumference. The attachment of these polymers to the cytoplasmic membrane requires an actin homolog, FtsA, which also forms dynamic polymers that directly bind to FtsZ. Recent evidence indicates that FtsA and FtsZ regulate each other’s oligomeric state inE. colito control the progression of cytokinesis, including the recruitment of septum synthesis proteins. In this review, we focus on recent advances in our understanding of protein-protein association between FtsZ and FtsA in the initial stages of divisome function, mainly in the well-characterizedE. colisystem.

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DrpB (YedR) Is a Nonessential Cell Division Protein in Escherichia coli

Journal of Bacteriology ◽

10.1128/jb.00284-20 ◽

2020 ◽

Vol 202 (23) ◽

Author(s):

Atsushi Yahashiri ◽

Jill T. Babor ◽

Ariel L. Anwar ◽

Ryan P. Bezy ◽

Evan W. Piette ◽

...

Keyword(s):

Escherichia Coli ◽

Cell Division ◽

Ionic Strength ◽

Bacterial Cell ◽

Enteric Bacteria ◽

High Ionic Strength ◽

Bacterial Cell Division ◽

Content Type ◽

E Coli ◽

Low Ionic Strength

ABSTRACT We report that the small Escherichia coli membrane protein DrpB (formerly YedR) is involved in cell division. We discovered DrpB in a screen for multicopy suppressors of a ΔftsEX mutation that prevents divisome assembly when cells are plated on low ionic strength medium, such as lysogeny broth without NaCl. Characterization of DrpB revealed that (i) translation initiates at an ATG annotated as codon 22 rather than the GTG annotated as codon 1, (ii) DrpB localizes to the septal ring when cells are grown in medium of low ionic strength but localization is greatly reduced in medium of high ionic strength, (iii) overproduction of DrpB in a ΔftsEX mutant background improves recruitment of the septal peptidoglycan synthase FtsI, implying multicopy suppression works by rescuing septal ring assembly, (iv) a ΔdrpB mutant divides quite normally, but a ΔdrpB ΔdedD double mutant has a strong division and viability defect, albeit only in medium of high ionic strength, and (v) DrpB homologs are found in E. coli and a few closely related enteric bacteria, but not outside this group. In sum, DrpB is a poorly conserved nonessential division protein that improves the efficiency of cytokinesis under suboptimal conditions. Proteins like DrpB are likely to be a widespread feature of the bacterial cell division apparatus, but they are easily overlooked because mutants lack obvious shape defects. IMPORTANCE A thorough understanding of bacterial cell division requires identifying and characterizing all of the proteins that participate in this process. Our discovery of DrpB brings us one step closer to this goal in E. coli.

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Insights into bacterial cell division from a structure of EnvC bound to the FtsX periplasmic domain

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.2017134117 ◽

2020 ◽

Vol 117 (45) ◽

pp. 28355-28365

Author(s):

Jonathan Cook ◽

Tyler C. Baverstock ◽

Martin B. L. McAndrew ◽

Phillip J. Stansfeld ◽

David I. Roper ◽

...

Keyword(s):

Cell Division ◽

Atpase Activity ◽

Mutational Analysis ◽

Coiled Coil ◽

Inhibition Mechanism ◽

Bacterial Cell Division ◽

E Coli ◽

Daughter Cells ◽

Periplasmic Domain

FtsEX is a bacterial ABC transporter that regulates the activity of periplasmic peptidoglycan amidases via its interaction with the murein hydrolase activator, EnvC. InEscherichia coli, FtsEX is required to separate daughter cells after cell division and for viability in low-osmolarity media. Both the ATPase activity of FtsEX and its periplasmic interaction with EnvC are required for amidase activation, but the process itself is poorly understood. Here we present the 2.1 Å structure of the FtsX periplasmic domain in complex with its periplasmic partner, EnvC. The EnvC-FtsX periplasmic domain complex has a 1-to-2 stoichiometry with two distinct FtsX-binding sites located within an antiparallel coiled coil domain of EnvC. Residues involved in amidase activation map to a previously identified groove in the EnvC LytM domain that is here found to be occluded by a “restraining arm” suggesting a self-inhibition mechanism. Mutational analysis, combined with bacterial two-hybrid screens and in vivo functional assays, verifies the FtsEX residues required for EnvC binding and experimentally test a proposed mechanism for amidase activation. We also define a predicted link between FtsEX and integrity of the outer membrane. Both the ATPase activity of FtsEX and its periplasmic interaction with EnvC are required for resistance to membrane-attacking antibiotics and detergents to whichE. coliwould usually be considered intrinsically resistant. These structural and functional data provide compelling mechanistic insight into FtsEX-mediated regulation of EnvC and its downstream control of periplasmic peptidoglycan amidases.

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