Type-III protein secretion systems are utilized by gram-negative pathogens to secrete building blocks of the bacterial flagellum, virulence effectors from the cytoplasm into host cells, and structural subunits of the needle complex. The flagellar type-III secretion apparatus utilizes both the energy of the proton motive force and ATP hydrolysis to energize substrate unfolding and translocation....

We present structural and electrical properties for p-type and n-type layers grown close to the transition between a-Si:H and nc-Si:H onto different substrates: Corning 1737 glass, ZnO:Al coated glass and stainless steel. Both crystalline fraction and dark conductivity at room temperature exhibited a transition from a-Si:H to nc-Si:H, which was clearly dependent on the substrate used. Stainless...

the algae of gargar river (one of branches of karoon river) which were investigated in samples collected from habitats (epilithic, epiphytic, epipelic) at eleven station between december 2004 and september 2005.this river receive types of sewage such as municipal wastewater, agriculture and aquaculture wastewater the flora consisted of 5 class and 24 genera belonging to the bacillariophycea (12...

Single crystals consisting various surface morphologies and epitaxial structures were applied to investigate the effect of other phase regions in the vicinity of a given tethered chains-covered area having a certain molecular weight of amorphous brushes. The designed experiments demonstrated that regardless of the type of surface morphology (patterned and especial mixed-brushes, homo and co...

determination of streptokinase activity is usually accomplished through two assay methods: a) clot lysis, b) chromogenic substrate assay. in this study the biological activity of two streptokinase products, namely streptase®, which is a native product and heberkinasa®, which is a recombinant product, was determined against the third international reference standard using the two forementioned a...

Type IV P-type ATPases (P4-ATPases) catalyze translocation of phospholipid across a membrane to establish an asymmetric bilayer structure with phosphatidylserine (PS) and phosphatidylethanolamine (PE) restricted to the cytosolic leaflet. The mechanism for how P4-ATPases recognize and flip phospholipid is unknown, and is described as the "giant substrate problem" because the canonical substrate ...

Using the energy of ATP hydrolysis, ABC transporters catalyze the trans-membrane transport of molecules. In bacteria, these transporters partner with a high-affinity substrate-binding protein (SBP) to import essential micronutrients. ATP binding by Type I ABC transporters (importers of amino acids, sugars, peptides, and small ions) stabilizes the interaction between the transporter and the SBP,...

18 O isotope exchange measurements of photosystem II (PSII) in thylakoids from wild-type and mutant Synechocystis have been performed to investigate binding of substrate water to the high-affinity Mn4 site in the oxygen-evolving complex (OEC). The mutants investigated were D1-D170H, a mutation of a direct ligand to the Mn4 ion, and D1-D61N, a mutation in the second coordination sphere. The subs...

An enzyme's substrate specificity is one of its most important characteristics. The quantitative comparison of broad-specificity enzymes requires the selection of a homogenous set of substrates for experimental testing, determination of substrate-specificity data and analysis using multivariate statistics. We describe a systematic analysis of the substrate specificities of nine wild-type and fo...