Studies of key catabolic enzymes indicate that the anammox reaction takes place inside the anammoxosome, an organelle-like membranous compartment of anammox bacteria. The anammoxosome has also been suggested as a site for ATP synthesis. A lipid-based protein immobilization Z-VAD-FMK cell line technique, previously used to identify proteins essential for the anammox reaction, was in this study used to select linear epitopes for antibodies specifically targeted against an identified ATPase. The approach of using

proteomics and bioinformatics as tools for selecting antibody targets for immunolocalization provides an important alternative to traditional methods for selection of specific antibodies. Immunogold electron microscopy and statistical evaluations ABT-888 indicated that the antibodies against the ATPase were exclusively found associated with the anammoxosome membrane. This provides strong evidence for ATP synthesis by an intracellular proton motive force in anammox bacteria. Within prokaryotes, an ATP synthase

associated with an intracellular compartment is a feature unique for anammox bacteria. “
“Pseudomonas syringae pv. tomato DC3000, a plant pathogenic gram-negative bacterium, employs the type III secretion system (T3SS) to cause disease in tomato and Arabidopsis and to induce the hypersensitive response in nonhost plants. The expression of T3SS is regulated by the HrpL extracytoplasmic sigma factor. Expression of HrpL is controlled by transcriptional

activators HrpR PAK5 and HrpS and negative regulator HrpV. In this study, we analysed the organization of HrpRS and HrpV regulatory proteins and interplay between them. We identified one key residue I26 in HrpS required for repression by HrpV. Substitution of I26 in HrpS abolishes its interaction with HrpV and impairs interactions between HrpS and HrpR and the self-association of HrpS. We show that HrpS self-associates and can associate simultaneously with HrpR and HrpV. We now propose that HrpS has a central role in the assembly of the regulatory HrpRSV complex. Deletion analysis of HrpR and HrpS proteins showed that C-terminal parts of HrpR and HrpS confer determinants indispensable for their self-assembly. “
“Polymyxa spp. are obligate biotrophs belonging to the plasmodiophorid group, responsible for transmitting a large number of plant viruses to many crop species. Their obligate nature makes them difficult to study. Controlled environment experiments were used to investigate the potential of infection of Arabidopsis thaliana by Polymyxa spp. to provide a more tractable system. Two ecotypes of Arabidopsis, Columbia and Landsberg erecta, were grown in soils known to be infested with Polymyxa. At the end of a 2-month growth period, both ecotypes were found to harbour Polymyxa-like structures or spores.