Microbial metabolism of C1 and C2 compounds. The involvement of glycollate in the metabolism of ethanol and of acetate by <i>Pseudomonas</i> AM1

Dunstan, P M; Anthony, Christopher; Drabble, W. T.

doi:10.1042/bj1280099

Cited by 66 publications

(56 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Cell extracts were prepared as described by Southgate & Goodwin (1989). Methanol dehydrogenase was assayed polarographically by the method of Dunstan et al (1972), as modified by Tatra & Goodwin (1985) and Southgate & Goodwin (1989). Methylamine dehydrogenase was also assayed polarographically, using a method based on that of Eady & Large (1968) as modified by .…”

Section: Methodsmentioning

confidence: 99%

Investigation of Thermolabile Variants of the Methanol and Methylamine Dehydrogenases of Methylophilus Methylotrophus and the Effect of an 11{middle dot}5 kbp Region of the Chromosome on the Stability of these Enzymes

Hutchinson

Goodwin

1993

Journal of General Microbiology

View full text Add to dashboard Cite

The thermal stabilities in vitro of the methylamine and methanol dehydrogenases of Methylophilus methylotrophus varied, depending on the conditions in which the organism was grown. Methylamine dehydrogenase activity was more stable in extracts of cells grown on methylamine plus NH,+ or on methanol plus methylamine than when methylamine provided the sole carbon and nitrogen source. In contrast, the methanol dehydrogenase activity in extracts of methylamine-grown cells was more stable than that from cells grown on medium containing methanol with either NHt or methylamine as the nitrogen source. The stability of thermolabile forms of the dehydrogenases present in extracts of mutants which have temperature-sensitive defects in the oxidation of C, compounds also varied with the growth conditions. When cosmid pAD833, which complemented these temperature-sensitive mutants, was present during growth of the wild-type strain on methylamine, the thermal stabilities of both methylamine and methanol dehydrogenases increased. However, the effects of subclones of pAD833 were complex and our results indicate that the DNA region carried on this cosmid encodes gene products which can both increase and decrease the in vitro thermal stability of enzymes involved in C, metabolism.

show abstract

Section: Methodsmentioning

confidence: 99%

Investigation of Thermolabile Variants of the Methanol and Methylamine Dehydrogenases of Methylophilus Methylotrophus and the Effect of an 11{middle dot}5 kbp Region of the Chromosome on the Stability of these Enzymes

Hutchinson

Goodwin

1993

Journal of General Microbiology

View full text Add to dashboard Cite

show abstract

“…This pathway is similar to the glyoxylate cycle (Kornberg, 1959), except in the way in which acetyl-CoA is converted to glyoxylate; Pseudomonas AMI does not synthesize detectable amounts of isocitrate lyase under any growth conditions yet tested (Large & Quayle, 1963;Dunstan et al, 1972) and the mechanism of this oxidation of acetate to glyoxylate is not known. Salem et al (1973b) have pointed out that the malate synthase activity measured in crude extracts of Pseudomonas AMI might be due to a coupling of malyl-CoA lyase which catalyses the reversible reaction (equation I) ) with a malyl-CoA hydrolase (equation 2 ) or acyl-CoA transferase, e.g.…”

Section: Introductionmentioning

confidence: 99%

Synthesis and Hydrolysis of Malyl-Coenzyme A by Pseudomonas AM1: an Apparent Malate Synthase Activity

Cox

Quayle

1976

Journal of General Microbiology

View full text Add to dashboard Cite

“…The assimilation of C1 units by this pathway requires continuous regeneration of glyoxylate from acetyl-CoA and can be achieved, in principle, via the well-known glyoxylate cycle (10). However, Dunstan and coworkers (11)(12)(13)(14) showed in 1972 and 1973 that M. extorquens AM1 lacks the key enzyme of the glyoxylate cycle, isocitrate lyase, but has an alternative route involving oxidation of acetate to glyoxylate that functions during growth on both C1 and C2 compounds. Also, other organisms, including the photosynthetic Rhodobacter sphaeroides are known to require an alternative to the glyoxylate cycle when growing on C2 substrates or on substrates that are converted into acetyl-CoA to enter central metabolism (15-18).…”

mentioning

confidence: 99%

Demonstration of the ethylmalonyl-CoA pathway by using ¹³ C metabolomics

Peyraud

Kiefer

Christen

et al. 2009

Proc. Natl. Acad. Sci. U.S.A.

217

242

View full text Add to dashboard Cite

The assimilation of one-carbon (C1) compounds, such as methanol, by serine cycle methylotrophs requires the continuous regeneration of glyoxylate. Instead of the glyoxylate cycle, this process is achieved by a not yet established pathway where CoA thioesters are known to play a key role. We applied state-of-the-art metabolomics and 13 C metabolomics strategies to demonstrate how glyoxylate is generated during methylotrophic growth in the isocitrate lyase-negative methylotroph Methylobacterium extorquens AM1. High-resolution mass spectrometry showed the presence of CoA thioesters specific to the recently proposed ethylmalonyl-CoA pathway. The operation of this pathway was demonstrated by short-term 13 C-labeling experiments, which allowed determination of the sequence of reactions from the order of label incorporation into the different CoA derivatives. Analysis of 13 C positional enrichment in glycine by NMR was consistent with the predicted labeling pattern as a result of the operation of the ethylmalonyl-CoA pathway and the unique operation of the latter for glyoxylate generation during growth on methanol. The results also revealed that 2 molecules of glyoxylate were regenerated in this process. This work provides a complete pathway for methanol assimilation in the model methylotroph M. extorquens AM1 and represents an important step toward the determination of the overall topology of its metabolic network. The operation of the ethylmalonyl-CoA pathway in M. extorquens AM1 has major implications for the physiology of these methylotrophs and their role in nature, and it also provides a common ground for C1 and C2 compound assimilation in isocitrate lyase-negative bacteria.13 C labeling ͉ CoA ester ͉ methylotroph ͉ one-carbon metabolism ͉ glyoxylate regeneration M ethylotrophic bacteria are organisms capable of using reduced carbon compounds, such as methanol or methane, as sole sources of carbon and energy, and they play a key role in carbon cycling in their environment. They also represent promising organisms in biotechnology for the conversion of one-carbon (C1) substrates to value-added products (1). The elucidation of the mechanisms enabling growth on reduced C1 compounds of Methylobacterium extorquens AM1, one of the most studied methylotrophs, has been a longstanding goal, and although great progress has been made (2-5), it is still not fully achieved. A key point has been to understand how the bacterium incorporates C1 units into cell material. The serine cycle was elucidated in this organism during the early 1960s by Quayle and coworkers (6-9). The assimilation of C1 units by this pathway requires continuous regeneration of glyoxylate from acetyl-CoA and can be achieved, in principle, via the well-known glyoxylate cycle (10). However, Dunstan and coworkers (11)(12)(13)(14) showed in 1972 and 1973 that M. extorquens AM1 lacks the key enzyme of the glyoxylate cycle, isocitrate lyase, but has an alternative route involving oxidation of acetate to glyoxylate that functions during growth on both C1 and C2 co...

show abstract

Microbial metabolism of C1 and C2 compounds. The involvement of glycollate in the metabolism of ethanol and of acetate by Pseudomonas AM1

Cited by 66 publications

References 17 publications

Investigation of Thermolabile Variants of the Methanol and Methylamine Dehydrogenases of Methylophilus Methylotrophus and the Effect of an 11{middle dot}5 kbp Region of the Chromosome on the Stability of these Enzymes

Investigation of Thermolabile Variants of the Methanol and Methylamine Dehydrogenases of Methylophilus Methylotrophus and the Effect of an 11{middle dot}5 kbp Region of the Chromosome on the Stability of these Enzymes

Synthesis and Hydrolysis of Malyl-Coenzyme A by Pseudomonas AM1: an Apparent Malate Synthase Activity

Demonstration of the ethylmalonyl-CoA pathway by using ¹³ C metabolomics

Contact Info

Product

Resources

About

Microbial metabolism of C1 and C2 compounds. The involvement of glycollate in the metabolism of ethanol and of acetate by Pseudomonas AM1

Cited by 66 publications

References 17 publications

Investigation of Thermolabile Variants of the Methanol and Methylamine Dehydrogenases of Methylophilus Methylotrophus and the Effect of an 11{middle dot}5 kbp Region of the Chromosome on the Stability of these Enzymes

Investigation of Thermolabile Variants of the Methanol and Methylamine Dehydrogenases of Methylophilus Methylotrophus and the Effect of an 11{middle dot}5 kbp Region of the Chromosome on the Stability of these Enzymes

Synthesis and Hydrolysis of Malyl-Coenzyme A by Pseudomonas AM1: an Apparent Malate Synthase Activity

Demonstration of the ethylmalonyl-CoA pathway by using 13 C metabolomics

Contact Info

Product

Resources

About

Demonstration of the ethylmalonyl-CoA pathway by using ¹³ C metabolomics