To test the hypothesis that Hmp overexpression , and not that of other NsrR-regulated gene products ( such as ytfE , hcp -- hcr , tehA , tehB and ygbA ) is responsible for hypersensitivity to peroxynitrite , we determined the effect of peroxynitrite on a double mutant ( hmp and nsrR ) .
A novel NsrR-regulated gene designated STM1808 has been identified , along with hmp , hcp-hcr , yeaR-yoaG , ygbA and ytfE .
To determine the contribution of other NsrR-regulated genes to nitrosative-stress resistance , we constructed insertion mutations in hcp , ygbA , ytfE , STM1808 and yeaR ( Experimental Procedures ) .
These data confirm previous findings with regard to hmp , and additionally demonstrate that the NsrR-regulated ytfE and STM1808 genes contribute to Salmonella virulence .
We have identified a novel NsrR-regulated gene designated STM1808 , and demonstrated a role for specific NsrR-regulated genes in promoting growth during nitrosative-stress in-vitro ( hmp , STM1808 , ygbA and hcp ) and during systemic infection of mice in-vivo ( hmp , STM1808 , ytfE ) .
STM1808 and ytfE can be added to hmp as NsrR-regulated loci that contribute to Salmonella virulence ( Fig. 6 ) .