title: From famine to feast: the role of methylglyoxal production in Escherichia coli.
abstract: The enzyme methylglyoxal synthase (MGS) was partially purified from Escherichia coli extracts, and the amino-terminal sequence of candidate proteins was determined, based on the native protein being a tetramer of about 69 kDa. Database analysis identified an open reading frame in the E. coli genome, YccG, corresponding to a protein of 16.9 kDa. When amplified and expressed from a controlled promoter, it yielded extracts that contained high levels of MGS activity. MGS expressed from the trc promoter accumulated to approximately 20% of total cell protein, representing approximately 900-fold enhanced expression. This caused no detriment during growth on glucose, and the level of methylglyoxal (MG) in the medium rose to only 0.08 mM. High-level expression of MGS severely compromised growth on xylose, arabinose and glycerol. A mutant lacking MGS was constructed, and it grew normally on a range of carbon sources and on low-phosphate medium. However, the mutant failed to produce MG during growth on xylose in the presence of cAMP, and growth was inhibited.
authors.affiliation: Department of Molecular and Cell Biology, Institute of Medical Sciences, University of Aberdeen, UK.
authors.forename: S
authors.initials: S
authors.lastname: Tötemeyer
authors.forename: N A
authors.initials: NA
authors.lastname: Booth
authors.forename: W W
authors.initials: WW
authors.lastname: Nichols
authors.forename: B
authors.initials: B
authors.lastname: Dunbar
authors.forename: I R
authors.initials: IR
authors.lastname: Booth
mesh_terms: D019757:Carbon-Oxygen Lyases / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism*; D004926:Escherichia coli / Q000737:chemistry / Q000201:enzymology* / Q000235:genetics* / Q000254:growth & development; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial; D005947:Glucose / Q000378:metabolism; D005990:Glycerol / Q000378:metabolism; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D010710:Phosphates / Q000378:metabolism; D010957:Plasmids / Q000235:genetics; D011765:Pyruvaldehyde / Q000378:metabolism*; D014994:Xylose / Q000378:metabolism
chemical_list: D010710:Phosphates; D011765:Pyruvaldehyde; D014994:Xylose; D019757:Carbon-Oxygen Lyases; C021578:methylglyoxal synthase; D005947:Glucose; D005990:Glycerol