Complex regulation of urease formation from the two promoters of the ure operon of Klebsiella pneumoniae.

ABSTRACT: Klebsiella pneumoniae can use urea as the sole source of nitrogen, thanks to a urease encoded by the ureDABCEFG operon. Expression of this operon is independent of urea and is regulated by the supply of nitrogen in the growth medium. When cells were growth rate limited for nitrogen, the specific activity of urease was about 70 times higher than that in cells grown under conditions of excess nitrogen. Much of this nitrogen regulation of urease formation depended on the nitrogen regulatory system acting through the nitrogen assimilation control protein, NAC. In a strain deleted for the nac gene, nitrogen limitation resulted in only a 7-fold increase in the specific activity of urease, in contrast to the 70-fold increase seen in that of the wild type. The ure operon was transcribed from two p

SUBMITTER: Liu Q 

PROVIDER: S-EPMC2168754 | biostudies-literature | 2007 Nov

REPOSITORIES: biostudies-literature