The order of the ring: assembly of Escherichia coli cell division components

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Background: Before constriction ZipA anchors FtsZ to the E. coli inner membrane as part of the cell division proto-ring. Results: Dynamic FtsZ polymers shrink ZipA-containing vesicles whereas excess of ZipA invaginates the E. coli membrane destroying the permeability barrier. Conclusion: Constriction forces can be evidenced both in bacteria and in vesicles. Significance: Defined bacterial elements reproduce division functions when assembled in vitro.

Section: Methodsmentioning

confidence: 99%

Bacterial Division Proteins FtsZ and ZipA Induce Vesicle Shrinkage and Cell Membrane Invagination

Cabré

Sánchez-Gorostiaga

Carrara

et al. 2013

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“…For its assembly, three essential proteins, FtsZ, FtsA, and ZipA, are first gathered at midcell, forming a proto-ring attached to the inner membrane ( Fig. 1) (4). In the proto-ring structure, the cytoplasmic GTPase FtsZ is anchored to the membrane by its interaction with ZipA and FtsA.…”

Section: Overview Of Septationmentioning

confidence: 99%

In the Beginning, Escherichia coli Assembled the Proto-ring: An Initial Phase of Division

Rico

Krupka²,

Vicente

2013

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Cell division in Escherichia coli begins by assembling three proteins, FtsZ, FtsA, and ZipA, to form a proto-ring at midcell. These proteins nucleate an assembly of at least 35 components, the divisome. The structuring of FtsZ to form a ring and the processes that effect constriction have been explained by alternative but not mutually exclusive mechanisms. We discuss how FtsA and ZipA provide anchoring of the cytoplasmic FtsZ to the membrane and how a temporal sequence of alternative protein interactions may operate in the maturation and stability of the proto-ring. How the force needed for constriction is generated and how the proto-ring proteins relate to peptidoglycan synthesis remain as the main challenges for future research. Overview of SeptationCell division is the last event in the bacterial cell cycle. It takes place by producing a rigid transversal septum after the growth processes fully duplicate the contents of the cell. Septation is always preceded by segregation of the duplicated nucleoids, ensuring that each of the daughter cells contains a fully replicated chromosome. Specialized molecules control the positioning of the division machinery at midcell, preventing any harmful fragmentation that septum progression could cause on unsegregated nucleoids.The division machinery, the divisome, establishes a complex interacting network together with DNA, lipids, and peptidoglycan components. It comprises a variable number of proteins, depending on the bacterial species. These proteins have redundant multiple functions and connections serving as safeguards to complete division and to guarantee the efficiency and versatility of the process. Altogether, an efficient division process allows the proliferation of bacteria under a variety of conditions, and it is one of the reasons for their success in the environment. Free-living bacteria, such as Escherichia coli, have more elaborated divisomes, whereas those that need to grow as intracellular parasites, as such Mycoplasma genitalium, have streamlined ones (1, 2).The structure of the E. coli divisome as revealed by immunofluorescence images of dividing cells is called the division ring (3). For its assembly, three essential proteins, FtsZ, FtsA, and ZipA, are first gathered at midcell, forming a proto-ring attached to the inner membrane ( Fig. 1) (4). In the proto-ring structure, the cytoplasmic GTPase FtsZ is anchored to the membrane by its interaction with ZipA and FtsA. ZipA is a bitopic protein containing a transmembrane domain (5). FtsA is a protein of the actin family that associates with the membrane by a short amphipathic helix (6, 7). The assembly of the FtsZ ring is dependent on a continuous energy supply. The FtsZ ring requires either ZipA or FtsA (8). Although it can be formed in the presence of either of them, division is affected unless both are present (9). A maturation period takes place after the protoring is assembled and before the rest of the divisome proteins become incorporated (10). During maturation, the proto-ring assembly is not stable...

“…In most bacteria, the tubulin homologue FtsZ is the first cell division protein to position at the division site, leading to the assembly of a multiprotein complex called the divisome, which coordinates membrane constriction with septum formation (1,2). Polymerization of FtsZ into filaments is essential for its function, as it is thought to be the main force carrying out membrane constriction during the division process (3,4).…”

mentioning

confidence: 99%

Evidence That Bacteriophage λ Kil Peptide Inhibits Bacterial Cell Division by Disrupting FtsZ Protofilaments and Sequestering Protein Subunits

Hernández-Rocamora

Alfonso

Margolin

et al. 2015

Background: Kil peptide from bacteriophage targets FtsZ to prevent host cell division. Results: Kil disrupts FtsZ protofilaments producing shorter oligomers of variable size with reduced GTPase activity. Conclusion: At high concentrations, Kil likely inhibits FtsZ assembly via a subunit sequestration mechanism. Significance: This is the first biophysical study of how a bacteriophage disruptor of bacterial division inhibits FtsZ assembly.