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Rahamthulla S Shaik, Min Woo Sung, Stanislav Vitha, Andreas Holzenburg
Chloroplasts evolved from cyanobacterial endosymbiotic ancestors and their division is a complex process initiated by assembly of cytoskeletal FtsZ proteins into a ring structure at the division site (Z-ring). The cyanobacterial Z-ring positioning system (MinCDE proteins) is also conserved in chloroplasts except that MinC was lost and replaced by the eukaryotic ARC3. Both MinC and ARC3 act as negative regulators of FtsZ assembly, but ARC3 bears little sequence similarity with MinC. Here, light scattering assays, co-sedimentation, GTPase assay and transmission electron microscopy (TEM) in conjunction with single particle analysis have been used to elucidate the structure of ARC3 and its effect on its main target in chloroplast division: FtsZ2...
November 14, 2017: Biochemical Journal
Fernando Santos-Beneit, David M Roberts, Stuart Cantlay, Joseph R McCormick, Jeff Errington
The central player in bacterial cell division, FtsZ, is essential in almost all organisms in which it has been tested, with the most notable exception being Streptomyces. Streptomycetes differ from many bacteria in growing from the cell tip and undergoing branching, similar to filamentous fungi. Here we show that limited cell damage, either mechanical or enzymatic, leads to near complete destruction of mycelial microcolonies of a Streptomyces venezuelae ftsZ mutant. This result is consistent with a lack of ftsZ-dependent cross-walls and may be inconsistent with a recently proposed role for membrane structures in the proliferation of ftsZ mutants in other Streptomyces species...
November 9, 2017: Nature Communications
Patrick J Lariviere, Piotr Szwedziak, Christopher R Mahone, Jan Löwe, Erin D Goley
During bacterial division, polymers of the tubulin-like GTPase FtsZ assemble at midcell to form the cytokinetic Z-ring, which coordinates peptidoglycan (PG) remodeling and envelope constriction. Curvature of FtsZ filaments promotes membrane deformation in vitro, but its role in division in vivo remains undefined. Inside cells, FtsZ directs PG insertion at the division plane, though it is unclear how FtsZ structure and dynamics are mechanistically coupled to PG metabolism. Here we study FzlA, a division protein that stabilizes highly curved FtsZ filaments, as a tool for assessing the contribution of FtsZ filament curvature to constriction...
November 9, 2017: Molecular Microbiology
Handuo Shi, Alexandre Colavin, Marty Bigos, Carolina Tropini, Russell D Monds, Kerwyn Casey Huang
Size is a universally defining characteristic of all living cells and tissues and is intrinsically linked with cell genotype, growth, and physiology. Many mutations have been identified to alter cell size, but pleiotropic effects have largely hampered our ability to probe how cell size specifically affects fundamental cellular properties, such as DNA content and intracellular localization. To systematically interrogate the impact of cell morphology on bacterial physiology, we used fluorescence-activated cell sorting to enrich a library of hundreds of Escherichia coli mutants in the essential cytoskeletal protein MreB for subtle changes in cell shape, cumulatively spanning ∼5-fold variation in average cell volume...
October 23, 2017: Current Biology: CB
Kousik Sundararajan, Erin D Goley
The bacterial tubulin FtsZ2 polymerizes to form a discontinuous ring that drives bacterial cell division by directing local cell wall synthesis. FtsZ comprises a polymerizing GTPase domain, an intrinsically disordered C-terminal linker (CTL) and a C-terminal conserved peptide (CTC). FtsZ protofilaments align circumferentially in the cell, with the CTC mediating attachment to membrane-associated division proteins. The assembly of FtsZ protofilaments into dynamic clusters is critical for cell division, but the interactions between protofilaments and regulatory mechanisms that mediate cluster assembly and dynamics are unknown...
October 31, 2017: Journal of Biological Chemistry
Nazeh M Al-Abd, Zurainee Mohamed Nor, Quazim O Junaid, Marzida Mansor, M S Hasan, Mustafa Kassim
Lymphatic filariasis (LF) is a vector borne disease caused by parasitic worms such as Wuchereria bancrofti, Brugia malayi and B. timori, which are transmitted by mosquitoes. Current therapeutics to treat LF are mainly microfilarcidal, and lack activity against adult worms. This set back, poses a challenge for the control and elimination of filariasis. Thus, in this study the activities of caffeic acid phenethyl ester (CAPE) against the filarial worm B. pahangi and its bacterial endosymbiont, Wolbachia were evaluated...
October 25, 2017: Pathogens and Global Health
Daniel Vega Mendoza, William Margolin
ZipA is essential for cell division in Escherichia coli, acting early in the process to anchor polymers of FtsZ to the cytoplasmic membrane. Along with FtsA, FtsZ and ZipA form a proto-ring at midcell that recruits additional proteins to eventually build the division septum. Cells carrying the thermosensitive zipA1 allele divide fairly normally at 30°C in rich medium but cease dividing at temperatures above 34°C, forming long filaments. In a search for suppressors of zipA1, we found that deletions of specific genes involved in amino acid biosynthesis could partially cell rescue growth and division at 34°C or 37°C, but not at 42°C...
October 23, 2017: Journal of Bacteriology
Marta Sobrinos-Sanguino, Silvia Zorrilla, Begoña Monterroso, Allen P Minton, Germán Rivas
ZipA protein from Escherichia coli is one of the essential components of the division proto-ring that provides membrane tethering to the septation FtsZ protein. A sedimentation assay was used to measure the equilibrium binding of FtsZ-GDP and FtsZ-GTP to ZipA immobilized at controlled densities on the surface of microbeads coated with a phospholipid mixture resembling the composition of E. coli membrane. We found that for both nucleotide-bound species, the amount of bound FtsZ exceeds the monolayer capacity of the ZipA immobilized beads at high concentrations of free FtsZ...
October 20, 2017: Scientific Reports
Sonia Huecas, Erney Ramírez-Aportela, Albert Vergoñós, Rafael Núñez-Ramírez, Oscar Llorca, J Fernando Díaz, David Juan-Rodríguez, María A Oliva, Patricia Castellen, José M Andreu
FtsZ is a self-assembling GTPase that forms, below the inner membrane, the mid-cell Z-ring guiding bacterial division. FtsZ monomers polymerize head to tail forming tubulin-like dynamic protofilaments, whose organization in the Z-ring is an unresolved problem. Rather than forming a well-defined structure, FtsZ protofilaments laterally associate in vitro into polymorphic condensates typically imaged on surfaces. We describe here nanoscale self-organizing properties of FtsZ assemblies in solution that underlie Z-ring assembly, employing time-resolved x-ray scattering and cryo-electron microscopy...
October 17, 2017: Biophysical Journal
James C Walsh, Christopher N Angstmann, Iain G Duggin, Paul M G Curmi
The Min protein system creates a dynamic spatial pattern in Escherichia coli cells where the proteins MinD and MinE oscillate from pole to pole. MinD positions MinC, an inhibitor of FtsZ ring formation, contributing to the mid-cell localization of cell division. In this paper, Fourier analysis is used to decompose experimental and model MinD spatial distributions into time-dependent harmonic components. In both experiment and model, the second harmonic component is responsible for producing a mid-cell minimum in MinD concentration...
2017: PloS One
Tae Hwan Noh, Liu Sen, Jongki Hong, Joon-Hee Lee, Hyung Ryong Moon, Jee H Jung
Viriditoxin is a fungal secondary metabolite of the fungus Paecilomyces variotii derived from the inner tissues of the giant jellyfish Nemopilema nomurai. Viriditoxin exhibits antibacterial activity against Streptococcus iniae and Streptococcus parauberis, which are major pathogens of aqua cultured fish. Viriditoxin induced abnormal cell morphologies in the fish pathogens S. iniae and S. parauberis, presumably by inhibiting FtsZ polymerization as was previously observed in Escherichia coli. Synthetic analogues of viriditoxin, designed based on docking simulation results to FtsZ of Staphylococcus aureus, were prepared and compared with viriditoxin for antibacterial activity...
November 15, 2017: Bioorganic & Medicinal Chemistry Letters
Dong-Seok Lee, Pil Kim, Eung-Soo Kim, Younhee Kim, Heung-Shick Lee
Corynebacterium glutamicum WhcD plays an important regulatory role in cell division. Binding of WhcD to the promoter region of its target genes, such as ftsZ, was observed by electrophoretic mobility shift assays (EMSA) using purified fusion proteins; however, binding could only be observed in the presence of WhiA. Although WhcD alone did not bind to the DNA, it stimulated binding of WhiA to the promoter region of the cell division gene ftsZ. Binding of WhcD and WhiA to DNA did not occur in the presence of the oxidant diamide...
October 7, 2017: Antonie Van Leeuwenhoek
Luis Concha-Marambio, Paula Maldonado, Rosalba Lagos, Octavio Monasterio, Felipe Montecinos-Franjola
Cytokinesis is the last stage in the cell cycle. In prokaryotes, the protein FtsZ guides cell constriction by assembling into a contractile ring-shaped structure termed the Z-ring. Constriction of the Z-ring is driven by the GTPase activity of FtsZ that overcomes the energetic barrier between two protein conformations having different propensities to assemble into polymers. FtsZ is found in psychrophilic, mesophilic and thermophilic organisms thereby functioning at temperatures ranging from subzero to >100°C...
2017: PloS One
Pramod Kumar, Amarjeet Yadav, Itzhak Fishov, Mario Feingold
The Z-ring plays a central role in bacterial division. It consists of FtsZ filaments, but the way these reorganize in the ring-like structure during septation remains largely unknown. Here, we measure the effective constriction dynamics of the ring. Using an oscillating optical trap, we can switch individual rod-shaped E. coli cells between horizontal and vertical orientations. In the vertical orientation, the fluorescent Z-ring image appears as a symmetric circular structure that renders itself to quantitative analysis...
2017: Frontiers in Microbiology
Sutharsan Govindarajan, Orna Amster-Choder
The Sec system is responsible for protein insertion, translocation and secretion across membranes in all cells. The bacterial actin homolog MreB controls various processes, including cell wall synthesis, membrane organization and polarity establishment. Here we show that the two systems genetically interact and that components of the Sec system, especially the SecA motor protein, are essential for spatiotemporal organization of MreB in E. coli, as evidenced by the accumulation of MreB at irregular sites in Sec-impaired cells...
September 2017: PLoS Genetics
Adam W Westbrook, Xiang Ren, Murray Moo-Young, C Perry Chou
Hyaluronic acid (HA) is a high-value biopolymer used in the biomedical, pharmaceutical, cosmetic, and food industries. Current methods of HA production, including extraction from animal sources and streptococcal cultivations, are associated with high costs and health risks. Accordingly, the development of bioprocesses for HA production centered on robust "Generally Recognized as Safe (GRAS)" organisms such as Bacillus subtilis is highly attractive. Here, we report the development of novel strains of B. subtilis in which the membrane cardiolipin (CL) content and distribution has been engineered to enhance the functional expression of heterologously expressed hyaluronan synthase (HAS) of Streptococcus equisimilis (SeHAS), in turn, improving the culture performance for HA production...
September 23, 2017: Biotechnology and Bioengineering
Swayansiddha Tripathy, Mohammed Afzal Azam, Srikanth Jupudi, Susanta Kumar Sahu
FtsZ is an appealing target for the design of antimicrobial agent that can be used to defeat the multidrug-resistant bacterial pathogens. Pharmacophore modelling, molecular docking and molecular dynamics (MD) simulation studies were performed on a series of three-substituted benzamide derivatives. In the present study a five-featured pharmacophore model with one hydrogen bond acceptors, one hydrogen bond donors, one hydrophobic and two aromatic rings was developed using 97 molecules having MIC values ranging from ...
October 11, 2017: Journal of Biomolecular Structure & Dynamics
Alejandro M Labella, David R Arahal, Teresa Lucena, Manuel Manchado, Dolores Castro, Juan J Borrego
Three bacterial strains were isolated from liver and spleen of diseased farmed redbanded seabream (Pagrus auriga) in south-west Spain. Their partial 16S rRNA gene sequences clustered within those of the genus Photobacterium, showing high similarity (98.6-99.3 %) to the type strains of Photobacterium iliopiscarium, P. piscicola, P. kishitanii, P. aquimaris and P. phosphoreum. Multilocus sequence analysis using six housekeeping genes (gapA, topA, mreB, ftsZ, gyrB and 16S rRNA) confirmed the new strains as forming an independent branch with a bootstrap value of 100, likely to represent a novel species...
September 21, 2017: International Journal of Systematic and Evolutionary Microbiology
Danielle M Heller, Mrinalini Tavag, Ann Hochschild
The toxin components of toxin-antitoxin modules, found in bacterial plasmids, phages, and chromosomes, typically target a single macromolecule to interfere with an essential cellular process. An apparent exception is the chromosomally encoded toxin component of the E. coli CbtA/CbeA toxin-antitoxin module, which can inhibit both cell division and cell elongation. A small protein of only 124 amino acids, CbtA, was previously proposed to interact with both FtsZ, a tubulin homolog that is essential for cell division, and MreB, an actin homolog that is essential for cell elongation...
September 2017: PLoS Genetics
Younghoon Oh, Jennifer H Schreiter, Hiroki Okada, Carsten Wloka, Satoshi Okada, Di Yan, Xudong Duan, Erfei Bi
Localized extracellular matrix (ECM) remodeling is thought to stabilize the cleavage furrow and maintain cell shape during cytokinesis [1-14]. This remodeling is spatiotemporally coordinated with a cytoskeletal structure pertaining to a kingdom of life, for example the FtsZ ring in bacteria [15], the phragmoplast in plants [16], and the actomyosin ring in fungi and animals [17, 18]. Although the cytoskeletal structures have been analyzed extensively, the mechanisms of ECM remodeling remain poorly understood...
September 25, 2017: Current Biology: CB
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