• Journal of Life Science
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• v.15 no.2 s.69
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• pp.182-185
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• 2005

We used the IS1096 transposon to construct Mycobacterium bovis BCG mutants resistant to an antituberculosis drug PA-824 and isolated several different mutants. We identified the locations of the insertions and found that the insertions were at various sites including the genes for the PPE proteins. HPLC analyses of the extracts of these five PPE mutant cells showed that three mutants produced only F0, and intermediate for the synthetic pathway of coenzyme $F^{420}$, and the remaining two neither F0 nor $F^{420}$. These data suggest that the products of these PPE genes are somehow involved in the biosynthesis of the coenzyme $F^{420}$.

• The Plant Pathology Journal
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• v.33 no.3
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• pp.276-287
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• 2017

RcsA is a positive activator of extracellular polysaccharide (EPS) synthesis in the Enterobacteriaceae. The rcsA gene of the soft rot pathogen Pantoea sp. strain PPE7 in Pleurotus eryngii was cloned by PCR amplification, and its role in EPS synthesis and virulence was investigated. The RcsA protein contains 3 highly conserved domains, and the C-terminal end of the open reading frame shared significant amino acid homology to the helix-turn-helix DNA binding motif of bacterial activator proteins. The inactivation of rcsA by insertional mutagenesis created mutants that had decreased production of EPS compared to the wild-type strain and abolished the virulence of Pantoea sp. strain PPE7 in P. eryngii. The Pantoea sp. strain PPE7 rcsA gene was shown to strongly affect the formation of the disease symptoms of a mushroom pathogen and to act as the virulence factor to cause soft rot disease in P. eryngii.