Fig. 4

Effects of different activation proteins (ω, α, σ54, CarQ) on the growth (a), epothilone production (b) and the gene expression (c) of different M. xanthus mutants (a). The growth of different M. xanthus mutants on CYE plate. Mutants: YL1611 (ZE9::pSWdmxCas9-ω), YL1616 (ZE9::pSWmxdCas9-ω-p41sg5), YL1617 (ZE9::pSWmxdCas9-α), YL1618 (ZE9::pSWmxdCas9-σ54), YL1619 (ZE9::pSWmxdCas9-CarQ), YL1620 (ZE9::pSWmxdCas9-α-p41sg5), YL1621 (ZE9::pSWmxdCas9-σ54-p41sg5), YL1622 (ZE9::pSWmxdCas9-CarQ- p41sg5). b The yield and the summation of epothilones A and B in mutants (YL1616, YL1620, YL1621, YL1622) and M. xanthus ZE9. c RT-qPCR analysis of the seven genes for the biosynthesis of epothilones in M. xanthus strains at 48 h of incubation. The expressions of the seven genes in ZE9 were each set as 1, and the expressions of seven genes in mutant strains were the relative expressions to them. The error bars represent the standard deviation of three independent experiments. For statistical analysis between the ancestral type strain and mutant strains, the signals of ** and * mean p < 0.01 and p < 0.05, respectively