“Most bacterial chromosomes contain homologs of plasmid pa


“Most bacterial chromosomes contain homologs of plasmid partitioning (par) loci. These loci encode ATPases called ParA that are thought to contribute to the mechanical force required

for chromosome and plasmid find more segregation. In Vibrio cholerae, the chromosome II (chrII) par locus is essential for chrII segregation. Here, we found that purified ParA2 had ATPase activities comparable to other ParA homologs, but, unlike many other ParA homologs, did not form high molecular weight complexes in the presence of ATP alone. Instead, formation of high molecular weight ParA2 polymers required DNA. Electron microscopy and three-dimensional reconstruction revealed that ParA2 formed bipolar helical filaments on double-stranded DNA in a sequence-independent manner. These

filaments had a distinct change in check details pitch when ParA2 was polymerized in the presence of ATP versus in the absence of a nucleotide cofactor. Fitting a crystal structure of a ParA protein into our filament reconstruction showed how a dimer of ParA2 binds the DNA. The filaments formed with ATP are left-handed, but surprisingly these filaments exert no topological changes on the right-handed B-DNA to which they are bound. The stoichiometry of binding is one dimer for every eight base pairs, and this determines the geometry of the ParA2 filaments with 4.4 dimers per 120 angstrom pitch left-handed turn. Our findings will be critical for understanding how ParA proteins function in plasmid and chromosome segregation.”
“Our previous study has for the first time demonstrated that atopic dermatitis (AD) patients show enhanced plasma concentrations

of PF4 and beta-TG. In addition, it has been suggested that chemokines may be the markers of AD severity. The aim of this study was to determine whether enhanced platelet activation in active AD withdraws when the disease reaches ABT-737 cell line the clinical remission stage. Plasma PF-4 and beta-TG concentrations were studied in 10 AD patients and in 23 healthy controls. Patients were examined twice: first, during the active period, and next, during the clinical remission lasting for at least 6 months. Plasma PF-4 and beta-TG concentrations in patients upon AD remission were significantly lower as compared to active AD and did not differ significantly from the healthy subjects. Enhanced platelet activation is a transient phenomenon accompanying active AD and disappears during clinical remission. As with earlier data, the findings point to platelet activity in AD increasing during flare, falling following therapy and normalizing upon remission.”
“This study evaluated secondary caries and periodontal conditions associated with metal (MCs) and composite resin copings (RCs) of abutment teeth for overdentures. The rates of secondary caries and periodontal problems in 70 root copings (41 MCs, 29 RCs) in 35 patients were retrospectively investigated for a period of 6.9 years.

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