English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Klebsiella aerogenes strains with reduced levels ofd -amino acid dehydrogenase not only fail to use alanine as a growth substrate but also become sensitive to alanine in minimal media supplemented with glucose and ammonium. The inability of these mutant strains to catabolize the alanine provided in the medium interferes with both pathways of glutamate production. Alanine derepresses the nitrogen regulatory system (Ntr), which in turn represses glutamate dehydrogenase, one pathway of glutamate production. Alanine also inhibits the enzyme glutamine synthetase, the first enzyme in the other pathway of glutamate production. Therefore, in the presence of alanine, strains with mutations indadA (the gene that codes for a subunit of the dehydrogenase) exhibit a glutamate auxotrophy when ammonium is the sole source of nitrogen. The alanine catabolic operon ofKlebsiella aerogenes ,dadAB , was cloned, and its DNA sequence was determined. The clone complemented the alanine defects ofdadA strains. The operon has a high similarity to thedadAB operon ofSalmonella typhimurium and thedadAX operon ofEscherichia coli , each of which codes for the smaller subunit ofd -amino acid dehydrogenase and the catabolic alanine racemase. Unlike the cases forE. coli andS. typhimurium , thedad operon ofK. aerogenes is activated by the Ntr system, mediated in this case by the nitrogen assimilation control protein (NAC). A sequence matching the DNA consensus for NAC-binding sites is located centered at position −44 with respect to the start of transcription. The promoter of this operon also contains consensus binding sites for the catabolite activator protein and the leucine-responsive regulatory protein.

journal of bacteriology

Alanine Catabolism in <i>Klebsiella aerogenes</i> : Molecular Characterization of the <i>dadAB</i> Operon and Its Regulation by the Nitrogen Assimilation Control Protein

Alanine Catabolism in Klebsiella aerogenes : Molecular Characterization of the dadAB Operon and Its Regulation by the Nitrogen Assimilation Control Protein