ISSN:
1365-2958
Quelle:
Blackwell Publishing Journal Backfiles 1879-2005
Thema:
Biologie
,
Medizin
Notizen:
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.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1046/j.1365-2958.1998.00700.x
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