Disease relevance of pncB

• The pncB gene of Salmonella typhimurium was used to develop an overexpression system for nicotinate phosphoribosyltransferase (NAPRTase, EC 2.4.2.11), which forms nicotinate mononucleotide (NAMN) and PPi from nicotinate and alpha-D-5-phosphoribosyl-1-pyrophosphate (PRPP) [1].

High impact information on pncB

• An inverted repeat of the sequence TAAACAA observed in the proposed promoter region of pncB is also present in the promoter of nadA, which, like pncB, is also regulated by the NadR (NadI) repressor [2].
• No signal sequence was observed in the predicted NAPRTase primary structure, suggesting that the enzyme is not periplasmic [2].
• Likewise, the pyridine nucleotide salvage pathway is controlled at pncB [3].
• As NAD levels increase within the cell, the affinity of NadR for the operator regions of nadA, nadB, and pncB increases, repressing the transcription of these target genes [3].
• The nicotinic acid phosphoribosyltransferase locus pncB was located on the Salmonella typhimurium linkage map counterclockwise relative to pyrC [4].

Chemical compound and disease context of pncB

• The pncB locus of the pyridine nucleotide cycle of NAD biosynthesis in Salmonella typhimurium was examined in terms of genetic structure and regulation [5].

Biological context of pncB

• Identification of a cis-acting regulatory region in the pncB locus of Salmonella typhimurium [5].

Associations of pncB with chemical compounds

• It was found that addition of the pncB gene to the FDH system does not increase further the production of reduced metabolites because the system for NADH regeneration already reached the maximum theoretical yield of approximately 4 mol NADH/mol of glucose [6].

Regulatory relationships of pncB

• The nadR locus (99 min) controls the transcription of several genes involved with either the biosynthesis (nadAB) or recycling (pncB) of NAD in Salmonella typhimurium [7].

References