Authors: Renata Novakova Jana Bistakova Jan Kormanec
Publish Date: 2004/09/08
Volume: 182, Issue: 5, Pages: 388-395
Abstract
A spore pigment polyketide gene cluster whiESa was cloned from Streptomyces aureofaciens CCM3239 using a probe from the S coelicolor A32 whiE gene cluster Sequence analysis of a 4657bp DNA fragment revealed five open reading frames with the highest similarity to the S coelicolor A32 whiE locus responsible for spore pigment biosynthesis with conservation of the size and position of the genes The whiESa gene cluster was disrupted by a homologous recombination in S aureofaciens CCM3239 replacing the most important whiESaIII gene encoding ketosynthase with a thiostrepton resistance gene The mutation affected spore pigmentation In contrast to wildtype greypink spore pigmentation the mutant produced white spores although overall spore morphology was not affected Transcriptional analysis of whiESa revealed two divergently oriented promoters whiESap1 and whiESap2 upstream of the whiESaI and whiESaVIII genes respectively Both promoters were developmentally regulated in S aureofaciens CCM3239 They were induced at the late stages of differentiation during sporulation of aerial hyphae and were dependent upon early sporulationspecific sigma factor σRpoZ and putative transcription factor WhiB The level of the transcript originating from the whiESap2 promoter was substantially reduced in a sigF mutant of S aureofaciens CCM3239 indicating its dependence upon the late sporulation sigma factor σF Comparison of the whiE promoters in three different spore pigment polyketide clusters revealed a highly conserved region upstream of the −35 promoter region that may bind a transcriptional regulator
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