Gene replacement analysis of the butyrolactone autoregulator receptor (FarA) reveals that FarA acts as a Novel regulator in secondary metabolism of Streptomyces lavendulae FRI-5.
IM-2 [(2R,3R,1'R)-2-1'-hydroxybutyl-3-hydroxymethyl gamma-butanolide] is a gamma-butyrolactone autoregulator which, in Streptomyces lavendulae FRI-5, switches off the production of D-cycloserine but switches on the production of a blue pigment and several nucleoside antibiotics. To clarify the in vivo function of an IM-2-specific receptor (FarA) in the IM-2 signaling cascade of S. lavendulae FRI-5, a farA deletion mutant was constructed by means of homologous recombination. On several solid media, no significant difference in morphology was observed between the wild-type strain and the farA mutant (strain K104), which demonstrated that the IM-2-FarA system does not participate in the morphological control of S. lavendulae FRI-5. In liquid media, the farA mutant overproduced nucleoside antibiotics and produced blue pigment earlier than did the wild-type strain, suggesting that the FarA protein acts primarily as a negative regulator on the biosynthesis of these compounds in the absence of IM-2. However, contrary to the IM-2-dependent suppression of D-cycloserine production in the wild-type strain, overproduction of D-cycloserine was observed in the farA mutant, indicating for the first time that the presence of both IM-2 and intact FarA are necessary for the suppression of D-cycloserine biosynthesis.
Kitani
S
S
Department of Biotechnology, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan.
Yamada
Y
Y
Nihira
T
T
D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D002090:Butyrophenones / Q000378:metabolism*; D003470:Culture Media; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D016254:Mutagenesis, Insertional; D010641:Phenotype; D011956:Receptors, Cell Surface / Q000235:genetics / Q000378:metabolism*; D013302:Streptomyces / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism
D001426:Bacterial Proteins; D002090:Butyrophenones; D003470:Culture Media; D004268:DNA-Binding Proteins; D011956:Receptors, Cell Surface; C107544:farA protein, Streptomyces