The bacterial pathogen, Staphylococcus aureus, grows by dividing in two alternating orthogonal planes. How these cell division planes are positioned correctly is not known. Here we used chemical genetic screening to identify PcdA as a division plane placement factor.
View Article and Find Full Text PDFCytoskeletal proteins are classified as a group that is defined functionally, whose members are capable of polymerizing into higher order structures, either dynamically or statically, to perform structural roles during a variety of cellular processes. In eukaryotes, the most well-studied cytoskeletal proteins are actin, tubulin, and intermediate filaments, and are essential for cell shape and movement, chromosome segregation, and intracellular cargo transport. Prokaryotes often harbor homologs of these proteins, but in bacterial cells, these homologs are usually not employed in roles that can be strictly defined as 'cytoskeletal'.
View Article and Find Full Text PDFBacterial cell division is driven by the polymerization of the GTPase FtsZ into a contractile structure, the so-called Z-ring. This essential process involves proteins that modulate FtsZ dynamics and hence the overall Z-ring architecture. Actinobacteria like and lack known key FtsZ-regulators.
View Article and Find Full Text PDFFilamentous, heterocyst-forming cyanobacteria are multicellular organisms in which growth requires the activity of two interdependent cell types that exchange nutrients and regulators. Vegetative cells provide heterocysts with reduced carbon, and heterocysts provide vegetative cells with fixed nitrogen. Additionally, heterocyst differentiation from vegetative cells is regulated by inhibitors of differentiation produced by prospective heterocysts and heterocysts.
View Article and Find Full Text PDFStreptomyces are filamentous bacteria with a complex developmental life cycle characterized by the formation of spore-forming aerial hyphae. Transcription of the chaplin and rodlin genes, which are essential for aerial hyphae production, is directed by the extracytoplasmic function (ECF) σ factor BldN, which is in turn controlled by an anti-σ factor, RsbN. RsbN shows no sequence similarity to known anti-σ factors and binds and inhibits BldN in an unknown manner.
View Article and Find Full Text PDFHeterocyst-forming cyanobacteria grow as filaments that can be hundreds of cells long. Proteinaceous septal junctions provide cell-cell binding and communication functions in the filament. In sp.
View Article and Find Full Text PDFUnlabelled: Filamentous, heterocyst-forming cyanobacteria exchange nutrients and regulators between cells for diazotrophic growth. Two alternative modes of exchange have been discussed involving transport either through the periplasm or through septal junctions linking adjacent cells. Septal junctions and channels in the septal peptidoglycan are likely filled with septal junction complexes.
View Article and Find Full Text PDFHeterocyst-forming cyanobacteria are multicellular organisms that grow as filaments that can be hundreds of cells long. Septal junction complexes, of which SepJ is a possible component, appear to join the cells in the filament. SepJ is a cytoplasmic membrane protein that contains a long predicted periplasmic section and localizes not only to the cell poles in the intercellular septa but also to a position similar to a Z ring when cell division starts suggesting a relation with the divisome.
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