title: Methionine adenosyltransferase and ethionine resistance in Saccharomyces cerevisiae.
abstract: The methionine adenosyltransferase is repressed in Saccharomyces cerevisiae during growth in the presence of excess methionine. The relationship of this repression to the level of intracellular S-adenosylmethionine is discussed. In conjunction with these studies, an ethionine-resistant mutant has been investigated which has a low level of methionine adenosyltransferase under all conditions tested. The mechanism of ethionine resistance in the latter strain apparently depends on its inability to form large quantities of intracellular S-adenosylethionine. With respect to the methionine adenosyltransferase, there is no apparent interaction between ethionine-resistant and ethionine-sensitive alleles when both are present in the heterozygous diploid.
mesh_terms: D000255:Adenosine Triphosphate; D000483:Alleles; D003470:Culture Media; D004171:Diploidy; D005001:Ethionine / Q000008:administration & dosage / Q000378:metabolism / Q000494:pharmacology*; D006238:Haploidy; D008715:Methionine; D012436:S-Adenosylmethionine / Q000378:metabolism; D012440:Saccharomyces / Q000201:enzymology*; D012441:Saccharomyces cerevisiae / Q000201:enzymology / Q000254:growth & development; D014166:Transferases / Q000032:analysis / Q000096:biosynthesis* / Q000302:isolation & purification
chemical_list: D003470:Culture Media; D012436:S-Adenosylmethionine; D000255:Adenosine Triphosphate; D008715:Methionine; D014166:Transferases; D005001:Ethionine