Anaerobic regulation of pyruvate formate-lyase from Escherichia coli K-12.
The anaerobic regulation of the gene encoding pyruvate formate-lyase from Escherichia coli was investigated. Expression of a pfl'-'lacZ protein fusion demonstrated that the gene is subject to a 12-fold anaerobic induction which can be stimulated a further 2-fold by the addition of pyruvate to the growth medium. Construction of a strain deleted for pfl verified that either pyruvate or a metabolite of glycolysis functions as an inducer of pfl gene expression. Complete anaerobic induction required the presence of a functional fnr gene product. However, the dependence was not absolute since a two- to threefold anaerobic induction could still be observed in an fnr mutant. These results could be confirmed immunologically by analyzing the levels of pyruvate formate-lyase protein present in cells grown under various conditions. It was also shown that pfl'-'lacZ expression was partially repressed by nitrate and that this repression was mediated by the narL gene product.
D000123:Acetyltransferases / Q000235:genetics*; D000332:Aerobiosis; D000693:Anaerobiosis; D003001:Cloning, Molecular; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics*; D005786:Gene Expression Regulation; D005796:Genes; D005798:Genes, Bacterial; D010957:Plasmids
D000123:Acetyltransferases; C022560:formate C-acetyltransferase