Integration of the pSLT Plasmid into the Salmonella Chromosome Results in a Temperature-Sensitive Growth Defect Due to Aberrant DNA Replication.

ABSTRACT: A mutant of Salmonella enterica serovar Typhimurium was isolated that simultaneously affected two metabolic pathways as follows: NAD metabolism and DNA repair. The mutant was isolated as resistant to a nicotinamide analog and as temperature-sensitive for growth on minimal glucose medium. In this mutant, Salmonella's 94-kb virulence plasmid pSLT had recombined into the chromosome upstream of the NAD salvage pathway gene pncA This insertion blocked most transcription of pncA, which reduced uptake of the nicotinamide analog. The pSLT insertion mutant also exhibited phenotypes associated with induction of the SOS DNA repair system, including an increase in filamentous cells, higher exonuclease III and catalase activities, and derepression of SOS gene expression. Genome sequencing revealed incr

SUBMITTER: Wozniak CE 

PROVIDER: S-EPMC7515242 | biostudies-literature | 2020 Sep

REPOSITORIES: biostudies-literature