The C. glutamicum pMTXL1 transformants were selected and screened on plates containing kanamycin and X-gal. The C. glutamicum wild-type and ΔsigB strains transformed with pMTXL1 were grown in MCGC minimal medium containing kanamycin to mid-log phase. Pexidartinib mw The MCGC minimal medium was inoculated to a density of 5 × 106 cells mL−1, placed in a shaking incubator at
30 °C and grown to early stationary phase. Cells were harvested by centrifugation and washed twice with PBS. The pellet was stored at −70 °C. The frozen cells were thawed on ice and suspended in 1 mL Reporter Lysis Buffer (Promega). Total proteins were then prepared by the method described in Western blot analysis. Enzyme assay of β-galactosidase activity was carried
out with wild-type and ΔsigB strains transformed with pMTXL1 according to the instructions of the supplier (Promega). Corynebacterium glutamicum wild-type, KH4, and KH5 strains were grown in MCGC minimal medium containing 0.5% (w/v) isocitrate and 1% (w/v) glucose to mid-log phase. One milliliter of each culture at a density of approximately 5 × 106 cells mL−1 was used to inoculate MCGC minimal medium in the presence of 3 μM WR99210-HCl and check details placed in a shaking incubator at 30 °C. Susceptibility to WR99210-HCl was measured by monitoring optical density at 600 nm every 3 h using a spectrophotometer (Bio-Rad). To estimate the levels of ThyA and ThyX in cultured cells of C. glutamicum, antiserum was raised in rabbits inoculated with purified ThyA or ThyX. The proteins produced by the E. coli strains harboring the thyA or thyX gene of C. glutamicum were then subjected to SDS-PAGE and Western blotting. The anti-ThyA or anti-ThyX serum specifically reacted with a protein of the same molecular weight as ThyA or ThyX, respectively, demonstrating the specificity of the antiserum (data not shown). To investigate the level of the thyA and thyX gene product, Western blot analysis was performed with ThyA or ThyX antiserum on total protein from PAK6 wild-type, KH1, and KH2 strains of C. glutamicum.
The 29-kDa band representing ThyA was present in all strains, whereas the 27-kDa band corresponding to ThyX was absent in the KH1 strain and present in the KH2 strain (Fig. 2), indicating that thyA and thyX were expressed in C. glutamicum and that the disruption of thyX prevented the synthesis of full-length ThyX. It was reported that the ΔthyX strain lost viability much more rapidly in the stationary growth phase compared with the parental wild-type or the thyX-complemented strain, suggesting that the activity of the ThyX enzyme is important for growth during stationary phase. This mutant was viable without thymidine supplementation, suggesting that thyX is not an essential gene in C. glutamicum, and the expression of thyA and thyX could differ in response to different growth conditions (Park et al., 2010).