As a corollary, these genes are not involved in the formation of isochorismic acid from chorismic acid. In addition, we have shown that trpE2 is involved in the conversion of chorismic acid to isochorismic acid (Table 1). The gene product of trpE2 thus corresponds to ICS and would be equivalent
of PchA in P. aeruginosa (Gaille et al., 2002; Kunzler et al., 2005). In this study, the targeted mutagenesis has elucidated the roles of trpE2, entC and entD genes in the conversion of salicylic acid from chorismic acid. Hence, salicylic acid seems to have only one function, although its involvement in the recognition of iron and its transfer cannot be ruled out completely. However, since we observed the salicylate nonauxotrophy of the mutants, the most viable explanation for this is that the gene products of salicylate biosynthesis interact with other proteins of the mycobactin pathway, making the conversion of salicylate to mycobactin and carboxymycobactin Sorafenib nmr less efficient. The addition of salicylate (which cannot be converted to mycobactin and carboxymycobactin) at higher concentrations, over 5 μg mL−1, in the medium makes it toxic for the mutants, although the mechanism for this toxicity is not understood. With these studies, we suggest that the organization of salicylate biosynthesis is different between M. smegmatis (current study) Venetoclax mw and M. tuberculosis (Harrison et al., 2006). Distinct
from mbtI of M. tuberculosis, but in common with pchA of P. aeruginosa, trpE2 is coding for ICS in M. smegmatis. Hence, the conversion of chorismate to salicylic acid in M. smegmatis involves a multienzyme complex consisting of trpE2, entC and entD genes. Taken together, these data conclude that in M. smegmatis, the gene product of trpE2 corresponds to ICS; entC and entD code for salicylate synthase. We thank Overseas Research Studentships (UK) for a research studentship to N.N. We are indebted to Prof. Neil Stoker (Royal Veterinary College, London) for his invaluable suggestions in creating
knockout mutants and generously gifting p2NIL and pGOAL19 vectors. “
“Lactobacillus paraplantarum is a species phenotypically close to Lactobacillus Etomidate plantarum. Several PCR methods were evaluated to discriminate L. paraplantarum strains and among them, a PCR using an enterobacterial repetitive intergenic consensus (ERIC) sequence differentiated L. paraplantarum from other Lactobacillus species. In addition, a combination of ERIC and random amplified polymorphic DNA (RAPD) analysis distinguished among seven strains of L. paraplantarum tested. ERIC-PCR profiles showed several strain-specific DNA fragments in L. paraplantarum, among them, a 2.2-kb ERIC marker, termed LpF1, found to be specific to strain FBA1, which improved the skin integrity in an animal model. The LpF1 encodes three proteins similar to Lactobacillus fermentum AroA, TyrA, and AroK, which are involved in the shikimate pathway.