This study reveals that components of the yeast ERAD-L pathway can discriminate between two subtly different forms of the same toxin substrate. Although precytosolic requirements are similar for both toxin structures, there is a divergence in fate on the cytosolic face of the ER membrane.

Aims: To determine the sensitivity of five strains of Staphylococcus aureus to five essential oils (EOs) and to investigate the anti-biofilm activity of lemongrass and grapefruit EOs. Methods and Results: Antimicrobial susceptibility screening was carried out using the disk diffusion method. All of the strains tested were susceptible to lemongrass, grapefruit, bergamot and lime EOs with zones of inhibition varying from 2Á85 to 8Á60 cm although they were resistant to lemon EO. Lemongrass EO inhibited biofilm formation at 0Á125% (v/v) as measured by colorimetric assay and at 0Á25% (v/v) no metabolic activity was observed as determined by 2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide (XTT) reduction. Grapefruit EO did not show any anti-biofilm activity. Following exposure to lemongrass EO extensive disruption to Staph. aureus biofilms was shown under scanning electron microscopy. Conclusions: In comparison to the other EOs tested, lemongrass exhibited the most effective antimicrobial and anti-biofilm activity. Significance and Impact of the Study: The effect of lemongrass EO highlights its potential against antibiotic resistant Staph. aureus in the healthcare environment.

Atherosclerosis is associated with a specific leukotriene receptor(s) capable of inducing hyperreactivity of human epicardial coronary arteries in response to LTC4 and LTD4.

The twin-arginine translocation (Tat) system mediates the transport of proteins across the bacterial plasma membrane and chloroplast thylakoid membrane. Operating in parallel with Sec-type systems in these membranes, the Tat system is completely different in both structural and mechanistic terms, and is uniquely able to catalyze the translocation of fully folded proteins across coupled membranes. TatC is an essential, multispanning component that has been proposed to form part of the binding site for substrate precursor proteins. In this study we have tested the importance of conserved residues on the periplasmic and cytoplasmic face of the Escherichia coli protein. We find that many of the mutations on the cytoplasmic face have little or no effect. However, substitution at several positions in the extreme N-terminal cytoplasmic region or the predicted first cytoplasmic loop lead to a significant or complete loss of Tat-dependent export. The mutated strains are unable to grow anaerobically on trimethylamine N-oxide minimal media and are unable to export trimethylamine-N-oxide reductase (TorA). The same mutants are completely unable to export a chimeric protein, comprising the TorA signal peptide linked to green fluorescent protein, indicating that translocation is blocked rather than cofactor insertion into the TorA mature protein. The data point to two essential cytoplasmic domains on the TatC protein that are essential for export.