Summary:Pseudomonas fluorescens UK1, and a mutant derived from it that can use methionine as its sole source of carbon and nitrogen, were used to study methionine degradation. Radioactive 2-oxomethionine, 2-oxobutyric acid and carbon dioxide comprised 95% of [1-14C]methionine consumed by the mutant. Demethio-lating activity was detected in both strains when they were grown with methionine.
The ability to grow on methionine depended on the decarboxylation of 2-oxobutyric acid derived from it. This decarboxylating activity was lost if the growth media contained an additional carbon source.
No evidence was obtained for the operation of the cystathionine pathway.
BaileyR. B., ParksL. W.1972; Response of the intracellular adenosine triphosphate pool of Saccharomyces cerevisiae to growth inhibition induced by excess l-methionine. Journal of Bacteriology III:542–546
BieleskiR. L., TurnerN. A.1966; Separation and estimation of amino acids in crude plant extracts by thin-layer chromatography. Analytical Biochemistry 17:278–293
Delavier-KlutckoC., FlavinM.1965; Enzymatic synthesis and cleavage of cystathionine in fungi and bacteria. Journal of Biological Chemistry 240:2537–2549
KallioR. E., LarsonA. D.1955; Methionine degradation by a species of Pseudomonas. In A Symposium on Amino Acid Metabolism pp. 616–631McElroyW. D., GlassH. B. Edited by Baltimore: Johns Hopkins Press;
KatzukiH., YoshidaT., TanegashimaC., TanakaS.1971; Improved direct method for determination of keto acids by 2,4-dinitrophenylhydrazine. Analytical Biochemistry 43:349–356
KreisW., HessionC.1973; Isolation and purification of l-methionine-α-deamino-γ-mercapto- methane-lyase (l-methioninase) from Clostridium sporogenes. Cancer Research 33:1862–1865
SegalW., StarkeyR. L.1953; Quantitative determination of methyl mercaptan, dimethyl disulphide and dimethyl sulphide in a gas mixture. Analytical Chemistry 25:1645–1648
YallI., NorrelS. A., JosephR., KnudsenR. C.1967; Effect of l-methionine and S-adenosyl-methionine on growth of an adenine mutant of Saccharomyces cerevisiae. Journal of Bacteriology 93:1551–1558