Mutants of Listeria monocytogenes with deletions in genes of the common branch of the biosynthesis pathway leading to aromatic compounds were constructed as possible virulence-attenuated carrier strains for protein antigens or vaccine DNA. aroA, aroB, and in particular aroE mutants showed strongly reduced growth rates in epithelial cells and even in rich culture media. The metabolism of the aro...

A DNA fragment encoding a kanamycin resistance determinant was used to insertionally inactivate the cloned aroA gene of Bordetella pertussis in Escherichia coli K-12, and a conjugative shuttle vector system based on the suicide vector pRTP1 was used to deliver the mutations from E. coli back into B. pertussis CN2992FS and BP1. The aroA mutation was introduced by allelic exchange into the chromo...

Subclinical infection of guinea pigs with isogenic wild type and aroA, htrA and aroA-htrA mutants of Salmonella enterica subspecies enterica serovar Abortusequi (S. Abortusequi) induced infertility, while mutants had little or no effect on conception rate in guinea pigs. Conception rate was significantly lower in guinea pigs inoculated with wild type (S-787) and aroA mutant of S. Abortusequi th...

The 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS; EC 2.5.1.19) is a key enzyme in the shikimate pathway for the production of aromatic amino acids and chorismate-derived secondary metabolites in plants, fungi, and microorganisms. It is also the target of the broad-spectrum herbicide glyphosate. Natural glyphosate resistance is generally thought to occur within microorganisms in a strong s...

The present study on a defined deletion aroA mutant (B-26) of Salmonella enterica subspecies enterica serovar Abortusequi (S. Abortusequi) for residual virulence and safety in experimental model revealed that the virulence of the strain was at no difference in any of the cell assays (caprine alveolar macrophages, bovine alveolar macrophages, guinea pig blood mononuclear cells and horse blood mo...

The chemolithoautotroph NT-26 oxidizes arsenite to arsenate by using a periplasmic arsenite oxidase. Purification and preliminary characterization of the enzyme revealed that it (i) contains two heterologous subunits, AroA (98 kDa) and AroB (14 kDa); (ii) has a native molecular mass of 219 kDa, suggesting an alpha2beta2 configuration; and (iii) contains two molybdenum and 9 or 10 iron atoms per...

We made delta aroA, delta purA, and delta aroA delta purA derivatives of a strain of Salmonella dublin and isolated a nalidixate-resistant mutant of each construct. An inoculum of each of the nearly isogenic nalidixate-resistant auxotrophs was administered to BALB/c mice by gavage. The ability of each strain to colonize, invade, persist in tissues, and evoke serum and mucosal antibody responses...

Glyphosate has been used globally as a safe herbicide for weed control. It inhibits 5-enolpyruvylshikimate-3-phosphate (EPSP) synthase (AroA), which is a key enzyme in the aromatic amino acid biosynthetic pathway in microorganisms and plants. A Pseudomonas putida strain, 4G-1, was isolated from a soil heavily contaminated by glyphosate in China. Its AroA-encoding gene (aroA) has been cloned, se...

The arrangement of the Escherichia coli serC (pdxF) and aroA genes into a cotranscribed multifunctional operon allows coregulation of two enzymes required for the biosynthesis of L-serine, pyridoxal 5'-phosphate, chorismate, and the aromatic amino acids and vitamins. RNase T2 protection assays revealed two major transcripts that were initiated from a promoter upstream from serC (pdxF). Between ...