Conformational changes in sigma 54 (sigma(54)) and sigma(54)-holoenzyme depend on nucleotide hydrolysis by an activator. We now show that sigma(54) and its holoenzyme bind to the central ATP-hydrolyzing domains of the transcriptional activators PspF and NifA in the presence of ADP-aluminum fluoride, an analog of ATP in the transition state for hydrolysis. Direct binding of sigma(54) Region I to...

sigma(E), a sporulation-specific transcription factor of Bacillus subtilis, is synthesized as an inactive proprotein with a 27-amino acid extension at its amino terminus. This "pro" sequence is removed by a developmentally regulated protease, but when present, it blocks sigma(E) activity, tethers sigma(E) to the bacterium's cytoplasmic membrane, and promotes sigma(E) stability. To investigate w...

The sigma binding site present in the Jurkat human T lymphocyte cell line was investigated. Jurkat cell membranes were found to have a single saturable binding site for [3H]haloperidol, a sigma ligand (dissociation constant, 3.9 +/- 0.3 nM). The binding of [3H]haloperidol was inhibited by several sigma ligands. Northern analysis and reverse transcription-polymerase chain reaction provided evide...

The sigma(54) promoter specificity factor is distinct from other bacterial RNA polymerase (RNAP) sigma factors in that it forms a transcriptionally silent closed complex upon promoter binding. Transcriptional activation occurs through a nucleotide-dependent isomerization of sigma(54), mediated via its interactions with an enhancer-binding activator protein that utilizes the energy released in A...

In this paper we define a discrete subset family of a topological space and basis sigma locally finite and sigma discrete. First, we prove an auxiliary fact for discrete family and sigma locally finite and sigma discrete basis. We also show the necessary condition for the Nagata Smirnov theorem: every metrizable space is T3 and has a sigma locally finite basis. Also, we define a sufficient cond...

The small regulatory protein Crl favors association of the stationary-phase sigma factor sigma(S) (RpoS) with the core enzyme polymerase and thereby increases sigma(S) activity. Crl has a major physiological impact at low levels of sigma(S). Here, we report that the Crl effects on sigma(S)-dependent gene expression, the H(2)O(2) resistance of Salmonella enterica serovar Typhimurium, and the res...

BACKGROUND Peritoneal carcinomatosis occurs in different cancer subtypes and is associated with a dismal prognosis. Some doubts remain whether the whole abdomen can be treated by regional hyperthermia, therefore we analyzed feasibility conducting a pilot study. METHODS A simulation of the abdominopelvic heat distribution in 11 patients with peritoneal carcinomatosis was done using the HyperPl...

We present a unified framework for understanding the compaction of colloidal gels under their own weight. The dynamics of the collapse are determined by the value of the gravitational stress sigma(g), as compared to the yield stress sigma(Y) of the network. For sigma(g)sigma(Y), th...

The six-sigma systems can promote the enterprise competitive ability, such as pursuing cost improvement, promoting quality, the customer’s satisfaction and valid strategy performance. This paper explored the synergies resulting from the combination of state-of-the art quality initiatives, lean and design for Six Sigma, and develop an integrated SCOR with lean and design for Six Sigma methodolog...

this paper presents a comparative analysis between two current control strategies, constant source power and generalized fryze current, used in active power filter (apf) applications having three different modulation methods. the hysteresis band (hb) and first-order delta-sigma modulation (dsm) as well as the second-order dsm is applied. the power section of the active power filter is viewed as...