earticle

영어

wblA (SCO3579) is a pleiotropic down-regulator of antibiotic biosynthesis in Streptomyces
species, as well as modulates morphological differentiation (Kang et al. 2007). Although wblA is notable pleiotropic down-regulator in valuable secondary metabolite production, these regulatory networks are still largely unknown. In this study, total cosmid DNA library screening in doxorubicin (DXR)-producing S. peucetius resulted in the isolation of S. peucetius wblA gene (named wblA-spe). To examine biological significance of the wblA-spe on DXR production, the wblA-spe was disrupted from the chromosome of DXRoverproducing S. peucetius strain by PCR-targeting system, followed by quantitative DXR HPLC analysis. After the wblA-spe gene disruption, biosynthesis of DXR and DXR intermediate aklavinone were slightly enhanced. Furthermore, using Streptomyces interspecies DNA microarray analysis between the DXR high-producer S. peucetius strain and wblA-spe disruption mutant strain, several putative wblA-dependent genes were identified. To verify the biological significance of this comparative transcriptomics-guided targets, the five putative wblA-dependent target genes were individually cloned under the strong-and constitutive promoter(PermE*) of the Streptomyces integrative expression vector, followed by conjugation into S. coelicolor. Among the putative wblA-dependent genes tested, the overexpression of NADH dehydrogenase subunit, (SCO4571) conserved hypothetical protein (SCO4967), and putative oxidoreductase beta-subunit (SCO6569) in S. coelicolor enhanced biosynthesis of actinorhodin about 1.5-2-fold relative to that of S.coelicolor exconjugant harboring the empty vector alone. More detailed results will be discussed.