Disease relevance of nadB

• Genetic characterization and regulation of the nadB locus of Salmonella typhimurium [1].

High impact information on nadB

• The nadI protein regulates transcription of the nadA and nadB biosynthetic genes and modulates activity of the NMN permease; both regulatory activities respond to the internal pyridine nucleotide level [2].
• These mutants mapped far from nadB near the pnuA gene, which encodes a function required for nicotinamide mononucleotide transport [1].
• The nadB gene of Salmonella typhimurium complements the nicotinic acid auxotrophy of Shigella flexneri [3].
• A third class of uptake mutant, pnuC, isolated in a nadB pncA pnuB background, also failed to grow on NMN [4].
• Two of the pncB mutants appear to be affected in the expression of NAPRTase while several of the nadB mutants are apparently insensitive to feedback inhibition by internal NAD concentrations [5].

Biological context of nadB

• Secondary mutations which suppress the Pas- phenotype were found to reside in the following NAD-related loci; pncB, nadB and nadD [5].

Associations of nadB with chemical compounds

• Increases in nadAB transcription directly correlated with decreases in intracellular NAD(P) levels, and kinetic studies indicated that the NAD analogue 6-amino NAD was ineffective in repressing either nadA or nadB [6].

Regulatory relationships of nadB

• It has been reported that this gene and nadA are regulated by a positive regulatory protein encoded in the nadB region [1].

References