Phosphoribosyl diphosphate synthetase-independent NAD de novo synthesis in Escherichia coli: a new phenotype of phosphate regulon mutants
Open Access
- 1 February 1996
- journal article
- Published by American Society for Microbiology in Journal of Bacteriology
- Vol. 178 (3), 714-722
- https://doi.org/10.1128/jb.178.3.714-722.1996
Abstract
Phosphoribosyl diphosphate-lacking (delta prs) mutant strains of Escherichia coli require NAD, guanosine, uridine, histidine, and tryptophan for growth. NAD is required by phosphoribosyl diphosphate-lacking mutants because of lack of one of the substrates for the quinolinate phosphoribosyltransferase reaction, an enzyme of the NAD de novo pathway. Several NAD-independent mutants of a host from which prs had been deleted were isolated; all of them were shown to have lesions in the pstSCAB-phoU operon, in which mutations lead to derepression of the Pho regulon. In addition NAD-independent growth was dependent on a functional quinolinate phosphoribosyltransferase. The prs suppressor mutations led to the synthesis of a new phosphoryl compound that may act as a precursor for a new NAD biosynthetic pathway. This compound may be synthesized by the product of an unknown phosphate starvation-inducible gene of the Pho regulon because the ability of pst or phoU mutations to suppress the NAD requirement requires PhoB, the transcriptional activator of the Pho regulon.Keywords
This publication has 40 references indexed in Scilit:
- DNA Sequence and Analysis of 136 Kilobases of the Escherichia coli Genome: Organizational Symmetry around the Origin of ReplicationGenomics, 1993
- Gene regulation by phosphate in enteric bacteriaJournal of Cellular Biochemistry, 1993
- Phosphoribosylpyrophosphate (PRPP)‐less mutants of Escherichia coliMolecular Microbiology, 1989
- Phosphoribosylpyrophosphate synthetase of Bacillus subtilis. Cloning, characterization and chromosomal mapping of the prs geneGene, 1987
- Phosphate-controlled gene expression in Escherichia coli K12 using Mudl-directed lacZ fusionsJournal of Molecular Biology, 1982
- Fusions of the lac operon to the transfer RNA gene tyrT of Escherichia coliJournal of Molecular Biology, 1979
- Calcium-dependent bacteriophage DNA infectionJournal of Molecular Biology, 1970
- DNA replication and the division cycle in Escherichia coliJournal of Molecular Biology, 1967
- Genetic evidence on the nature of the repressor for alkaline phosphatase in E. coliJournal of Molecular Biology, 1963
- Genetic control of repression of alkaline phosphatase in E. coliJournal of Molecular Biology, 1961