Collection of regulogs for NrtR transcription factor

Transcription factor NrtR negatively controls metabolic pathways of NAD biosynthesis, salvage and recycling [18276643]. The NrtR regulon and its DNA-binding motif were discovered by application of the comparative genomic approach to the NAD biosynthetic genes in Cyanobacteria. Then NrtR regulons were reconstructed by the same approach in diverse taxonomic groups of bacteria that have an ortholog of the NrtR regulator. The DNA-binding motifs of NrtR showed significant variability between microbial lineages, although the common consensus could be traced for all of them. Regulators of the NrtR family are composed of an N-terminal Nudix-like effector domain, which is similar to the ADP-ribose pyrophosphatases from the Nudix family, and a C-terminal DNA-binding HTH-like domain. more

Bioinformatics predictions were experimentally validated by electophoretic mobility shift assay (EMSA) for two NrtR family representatives from Shewanella oneidensis and Synechocystis spp. It was also shown that ADP-ribose, a product of glycohydrolytic cleavage of NAD, acts as an inducer for the NrtR regulator. In addition to a major role in the direct regulation of NAD homeostasis, some members of NrtR family appear to have been recruited for the regulation of other metabolic pathways, including sugar pentoses utilization and biogenesis of phosphoribosyl pyrophosphate.