Open AccessMethionine catabolism in Saccharomyces cerevisiae
Author(s) -
Perpète Philippe,
Duthoit Olivier,
De Maeyer Simon,
Imray Louise,
Lawton Andrew I.,
Stavropoulos Konstantinos E.,
Gitonga Virginia W.,
Hewlins Michael J. E.,
Richard Dickinson J.
Publication year - 2006
Publication title -
fems yeast research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.991
H-Index - 92
eISSN - 1567-1364
pISSN - 1567-1356
DOI - 10.1111/j.1567-1356.2005.00005.x
Subject(s) - methionine , methanethiol , catabolism , biochemistry , saccharomyces cerevisiae , decarboxylation , butyrate , biology , yeast , methionine synthase , biosynthesis , amino acid , fermentation , enzyme , chemistry , sulfur , organic chemistry , catalysis
The catabolism of methionine to methionol and methanethiol in Saccharomyces cerevisiae was studied using 13 C NMR spectroscopy, GC‐MS, enzyme assays and a number of mutants. Methionine is first transaminated to α‐keto‐γ‐(methylthio)butyrate. Methionol is formed by a decarboxylation reaction, which yields methional, followed by reduction. The decarboxylation is effected specifically by Ydr380wp. Methanethiol is formed from both methionine and α‐keto‐γ‐(methylthio)butyrate by a demethiolase activity. In all except one strain examined, demethiolase was induced by the presence of methionine in the growth medium. This pathway results in the production of α‐ketobutyrate, a carbon skeleton, which can be re‐utilized. Hence, methionine catabolism is more complex and economical than the other amino acid catabolic pathways in yeast, which use the Ehrlich pathway and result solely in the formation of a fusel alcohol.