Record Details
Regulation of the terminal reactions for methionine biosynthesis in yeast
ScholarsArchive at Oregon State University
| Field | Value |
|---|---|
| Title | Regulation of the terminal reactions for methionine biosynthesis in yeast |
| Names |
Spence, Kemet Dean
(creator) Parks, Leo W. (advisor) |
| Date Issued | 1965-05-14 (iso8601) |
| Note | Graduation date: 1965 |
| Abstract | Studies were carried out to elucidate the mechanism of enzymatic control of methionine biosynthesis in Saccharomyces cerevisiae. Enzymatic studies demonstrated that, in addition to the methionine activating enzyme, the S-adenosylmethionine:homocysteine transmethylase enzyme was induced during cultivation in the presence of excess methionine. A similar, though reduced effect was observed when homocysteine and serine were present in the medium. The serine hydroxymethylase enzyme was repressed under these conditions. Ethionine-resistant mutants were isolated to facilitate these studies. These organisms were shown to possess a reduced ability for converting methionine to S-adenosylmethionine. These organisms accumulated more intracellular methionine than the wild-type strain. The mutants were also found to excrete more methionine into the medium than the parental strain. All mutants tested showed a reduced level of the transmethylase enzyme. Two showed a reduced level of the methionine activating enzyme. Studies which measured the accumulation and intracellular distribution of ethionine (ethyl-C¹⁴) and methionine (methyl-C¹⁴) were also carried out. The mutants were able to exclude' the analog from participation in most cellular processes. |
| Genre | Thesis/Dissertation |
| Topic | Methionine |
| Identifier | http://hdl.handle.net/1957/47853 |
