The mechanism by which a nonphotosynthetic bacterium Pseudomonas sp. (Shaw Strain MA) grows on the one-carbon source, methylamine, was investigated by comparing enzyme levels of cells grown on methylamine, to cells grown on acetate or succinate. Cells grown on methylamine have elevated levels of the enzymes serine hydroxymethyl transferase, serine dehydratase, malic enzyme, glycerate dehydrogenase and malate lyase (CoA acetylating ATP-cleaving). These enzymes, in conjunction with a constitutive glyoxylate transaminase, can account for the net conversion of two one-carbon units into acetyl CoA. Cells grown on acetate or methylamine, but not succinate, contain the enzyme isocitrate lyase; while cells grown on acetate or succinate, but not methylamine, contain significant levels of malate synthetase. These findings suggest that the acetyl CoA derived from one-carbon units in methylamine grown cells, condenses with oxalacetate to yield citrate and then isocitrate, followed by cleavage to succinate and glyoxylate. Thus, growth on methylamine is accomplished by the net synthesis of succinate from two molecules of methyamine and two molecules of CO2.
|Number of pages||7|
|Journal||Archives of Biochemistry and Biophysics|
|State||Published - Nov 1972|
Bibliographical noteFunding Information:
1 This work was supported in part by Grant No. 1391 from The Robert A. Welch Foundation, Houston, Texas, and Grant No. AM 13443 from the NIAMI> to L.B.H. 2 To whom correspondence should be addressed. 3 Recipient, of Research Career I)evelopment Award GM 70239 from the National Institute General Medical Science.
ASJC Scopus subject areas
- Molecular Biology