The yeast regulatory protein kinase, general control non-derepressible-2 (GCN2) plays a key role in general amino acid control. GCN2 phosphorylates the alpha subunit of the trimeric eukaryotic translation initiation factor-2 (eIF2), bringing about a decrease in the general rate of protein synthesis but an increase in the synthesis of GCN4, a transcription factor that promotes the expression of ...

Mixed rumen micro-organisms, maintained in continuous culture readily incorporated labelled HCO3- and acetate into amino acids. Labelled propionate, in contrast, was utilized only for isoleucine biosynthesis, but failed to label other amino acids to any significant extent. Evidence was obtained showing that in these mixed, i.e. symbiotic, cultures foward tricarboxylic acid-cycle reactions only ...

Enzymes that catalyze the condensation of acetyl coenzyme A and 2-oxo acids are likely to be important in two distinct metabolic pathways in Arabidopsis. These are the synthesis of isopropylmalate, an intermediate of Leu biosynthesis in primary metabolism, and the synthesis of methylthioalkylmalates, intermediates of Met elongation in the synthesis of aliphatic glucosinolates (GSLs), in seconda...

Amino acids are not only building blocks for proteins but serve as precursors for the synthesis of many metabolites with multiple functions in growth and other biological processes of a living organism. The biosynthesis of amino acids is tightly connected with central carbon, nitrogen and sulfur metabolism. Recent publication of genome sequences for two diatoms Thalassiosira pseudonana and Phae...

Stringent strains of Escherichia coli are shown to produce one, and usually two, 82P-labeled compounds specifically in response to amino acid starvation. This pattern of labeling is not observed in three derived relaxed strains. Comparison of properties of the system regulating the synthesis of these compounds with those of the amino acid control of RNA biosynthesis suggests that the unusual co...

Stringent strains of Escherichia coli are shown to produce one, and usually two, 82P-labeled compounds specifically in response to amino acid starvation. This pattern of labeling is not observed in three derived relaxed strains. Comparison of properties of the system regulating the synthesis of these compounds with those of the amino acid control of RNA biosynthesis suggests that the unusual co...