Regulation elements

Concentration of 14 Regulated Elements in Electric Arc Furnace Dust... 

Besides the Sleipner project, the In Salah project and the Weyburn project, there are many sites, especially in the United States, where C02 from natural and industrial sources is used commercially for enhanced oil recovery. Even if those projects allow a lot of technical experience to be gained, the appropriateness of their regulative element as an example for C02 storage in general is not given. 

To detoxify heavy metals, the liver contains metallothioneins, a group of cysteine-rich proteins with a high af nity for divalent metal ions such as Cd Cu Hg, and Zn T These metal ions also induce the formation of metallothioneins via a special metal-regulating element (MRE) in the gene s promoter (see p. 244). 

An increase in the hormone concentration is the main regulating element when a rapid activation of a signaling pathway is required. Hormones can be stored in the... 

This is a regulating element for expansion of the liquid refrigerant from liquefying pressure to compressing pressure. 

The system may be regarded as involving a Na+/Mg2+ co-catalysed phosphorylation step and a K+ catalysed dephosphorylation. Each phosphorylation/dephosphorylation step involves a pseudorotation of an Mg2+-stabilised 5-coordinate intermediate, resulting in transport of the alkali metal cations. The cation transport ability of the enzyme is a direct result of the enzymatic reactivity of the protein. There are three binding sites with high Na+ affinity and two with K+ affinity (occupied by Rb+ in the crystal structure determination). The structure (which is of the E2K state of the system) reveals that carboxy end of the a-subunit is held in a pocket in between transmembrane helices and acts as an unusual regulating element that controls sodium affinity and may be influenced by the membrane potential. 

The abnormality of this enzyme associated with hereditary nonspherocytic hemolytic anemia is an increase in activity in the erythrocyte. This results in the depletion of red cell ATP and hemolysis. Few cases with a thirtyfoid to seventyfold increase have been described. It is the only RBC enzymopathy that is inherited as an autosomal dominant disorder. The molecular mechanism of this disorder has not been identified. High levels of normal ADA mRNA were present, suggesting a mutation in an in cis transcriptional regulating element, which could not be identified. 

Internal exchange of iron is accomplished by the plasma protein transferrin. This 76 kDa /Ij-glycoprotein has 2 binding sites for ferric iron. Iron is delivered from transferrin to intracellular sites by means of specific transferrin receptors in the plasma membrane. The iron-transferrin complex binds to the receptor, and the ternary complex is taken up by receptor-mediated endocytosis. Iron subsequently dissociates in the acidic, intracellular vesicular compartment (the endosomes), and the receptor returns the apotransferrin to the cell surface, where it is released into the extracellular environment. Cells regulate their expression of transferrin receptors and intracellular ferritin in response to the iron supply. Apoferritin synthesis is regulated post-transcriptionally by 2 cytoplasmic binding proteins (IRP-1 and lRP-2) and an iron-regulating element on its mRNA (IRE). 

Resource limitations of productivity in wetlands and aquatic ecosystems have focused on inorganic nutrient availability and loading rates from drainage basins. Recently, research has shown that much of the nutrient bioavailability in the soil and water column is associated with nutrients bound in or with naturally dissolved organic compounds. Many of the nutrient and organic substrate limitations are focused on hydrolytic activity of enzymes. The role of enzymes in regulating elemental cycles is addressed in various chapters of this book. 

Zalani S, Coppage A, Holley-Guthrie E, Kenney S. The cellular YYl transcription factor binds a cis-acting, negatively regulating element in the Epstein-Barr vims BRLFl promoter. J ViroL 1997 71 3268-74. 

The Gram-positive human pathogen Streptococcus pneumoniae is a frequent causal agent of pneumonia, otitis, and meningitis. Thirty percent of S. pneumoniae clinical isolates are piliated due to carriage of the rlrA operon coding for three sortases, a regulating element and the structural... 

Stanewsky R., Jamison C.F., Plautz J.D., Kay S.A., and Hall J.C. 1997. Multiple circadian-regulated elements contribute to cycling period gene expression in Drosophila. EMBO J. 16 5006-5018. 

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