Abstract
In Escherichia coli, L-fucose is dissimilated via an inducible pathway mediated by L-fucose permease, L-fucose isomerase, L-fucose kinase, and L-fuculose 1-phosphate aldolase. The last enzyme cleaves the six-carbon substrate into dihydroxyacetone phosphate and L-lactaldehyde. Aerobically, lactaldehyde is oxidized to L-lactate by a nicotinamide adenine dinucleotide (NAD)-linked dehydrogenase. Anaerobically, lactaldehyde is reduced by an NADH-COUPLED REDUCTASE TO L-1,2-propanediol, which is lost into the medium irretrievably, even when oxygen is subsequently introduced. Propanediol excretion is thus the end result of a dismutation that permits further anaerobic metabolism of dihydroxy-acetone phosphate. A mutant selected for its ability to grow aerobically on propanediol as a carbon and energy source was reported to produce lactaldehyde reductase constitutively and at high levels, even aerobically. Under the new situation, this enzyme serves as a propanediol dehydrogenase. It was also reported that the mutant had lost the ability to grow on fucose. In the present study, it is shown that in wild-type cells the full synthesis of lactaldehyde dehydrogenase requires the presence of both molecular oxygen and a small molecule effector, and the full synthesis of lactaldehyde reductase requires anaerobiosis and the presence of a small molecule effector. The failure of mutant cells to grow on fucose reflects the impairment of a regulatory element in the fucose system that prevents the induction of the permease, the isomerase, and the kinase. The aldolase, on the other hand, is constitutively synthesized. Three independent fucose-utilizing revertants of the mutant all produce the permease, the isomerase, the kinase, as well as the aldolase, constitutively. These strains grow less well than the parental mutant on propanediol.
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- Cocks G. T., Aguilar T., Lin E. C. Evolution of L-1, 2-propanediol catabolism in Escherichia coli by recruitment of enzymes for L-fucose and L-lactate metabolism. J Bacteriol. 1974 Apr;118(1):83–88. doi: 10.1128/jb.118.1.83-88.1974. [DOI] [PMC free article] [PubMed] [Google Scholar]
- DISCHE Z., BORENFREUND E. A new spectrophotometric method for the detection and determination of keto sugars and trioses. J Biol Chem. 1951 Oct;192(2):583–587. [PubMed] [Google Scholar]
- GHALAMBOR M. A., HEATH E. C. The metabolism of L-fucose. II. The enzymatic cleavage of L-fuculose 1-phosphate. J Biol Chem. 1962 Aug;237:2427–2433. [PubMed] [Google Scholar]
- GREEN M., COHEN S. S. Enzymatic conversion of L-fucose to L-fuculose. J Biol Chem. 1956 Apr;219(2):557–568. [PubMed] [Google Scholar]
- HEATH E. C., GHALAMBOR M. A. The metabolism of L-fucose. I. The purification and properties of L-fuculose kinase. J Biol Chem. 1962 Aug;237:2423–2426. [PubMed] [Google Scholar]
- HUFF E. The metabolism of 1,2-propanediol. Biochim Biophys Acta. 1961 Apr 15;48:506–517. doi: 10.1016/0006-3002(61)90048-8. [DOI] [PubMed] [Google Scholar]
- Sridhara S., Wu T. T., Chused T. M., Lin E. C. Ferrous-activated nicotinamide adenine dinucleotide-linked dehydrogenase from a mutant of Escherichia coli capable of growth on 1, 2-propanediol. J Bacteriol. 1969 Apr;98(1):87–95. doi: 10.1128/jb.98.1.87-95.1969. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Sridhara S., Wu T. T. Purification and properties of lactaldehyde dehydrogenase from Escherichia coli. J Biol Chem. 1969 Oct 10;244(19):5233–5238. [PubMed] [Google Scholar]
- Zagalak B., Frey P. A., Karabatsos G. L., Abeles R. H. The stereochemistry of the conversion of D and L 1,2-propanediols to propionaldehyde. J Biol Chem. 1966 Jul 10;241(13):3028–3035. [PubMed] [Google Scholar]