Synthesis of total RNA, DNA, and protein was followed in a
haploid yeast auxotroph during starvation for required amino acids
and uracil, and during shift-up and shift-down conditions.
During amino acid starvation, synthesis of macromolecular
constituents was not immediately affected, reflecting the presence
of large intracellular amino acid pools. Under...
Nutritional shift-up experiments have revealed many important
macromolecular interactions in bacteria. It has been shown that RNA
synthesis can be dissociated from protein and DNA synthesis. The
rates of protein synthesis were found to be, at a given temperature,
strictly dependent on the numbers of mature ribosomes present.
DNA synthesis...
Sterols of the yeast Saccharomyces cerevisiae are found in
membranes with a free C-3,β hydroxyl group or stored in lipid
droplets as esters of long-chain fatty acids. We have examined the
distribution of cholesterol into free sterol and steryl ester pools
of a sterol auxotrophic strain of Saccharomyces cerevisiae. Varying...
The generation of the methyl group of methionine, and is also involved in thymidylic acid and purine biosynthesis. The understanding of the mechanisms and controls involved in one-carbon metabolism is incomplete, and is complicated by the existence of conjugated folate cofactors containing up to seven glutamic acid residues. The information...
Methionine metabolism, leading to the biosynthesis of ethylene in Saccharomyces cerevisiae does not appear to involve S-adenosylmethionine (SAM) and aminocyclopropanecarboxylic acid (ACC), based on the lack of ethylene synthesis when both SAM and ACC were incubated in the presence and absence of cells. Thus, the mechanism leading to the formation...
The regulation of ergosterol biosynthesis in yeast has been
studied. The system has been examined for the presence of an end-product inhibition. Both anaerobically and aerobically grown cells
have been examined for this effect. A feedback inhibition of sterol
synthesis has been shown, but it appears to be a secondary...
An assay is described to measure sterol uptake in
Saccharomyces cerevisiae. This assay involves specific
binding of radioactively labelled sterol to actively
growing yeast cells.
It was found that uptake does not occur in stationary
cultures and that some growth is necessary for FY3 , a
sterol auxotroph, to take...
The halogen bond is a non-covalent, stabilizing interaction analogous to a hydrogen bond in which an anisotropically polarized halogen atom interacts
electrostatically with a Lewis base. Until very recently, the ability of halogens to form these stabilizing interactions in biological macromolecules was all but unknown, but
examples of halogen bonding...