II.Mechanism for Regulation of Chitinase Production by Allosamidin through a Two-component Regulatory System:Chitinase Inhibitor Allosamidin Is a Signal Molecule for Chitinase Production in Its Producing Streptomyces

摘要

In Streptomyces sp.AJ9463,a producer of chitinase inhibitor allosamidin,allosamidin strongly enhances production of the chitinase mainly secreted to the culture broth in a chitin medium.To clarify the mechanism for regulation of the chitinase production by allosamidin,a disruption experiment of genes encoding proteins constructing a two-component regulatory system present at 5'-upstream region of the chitinase gene was performed.In the disruptant obtained,allosamidin could not promote the chitinase production,but N,N'-diacetylchitobiose,which also enhances production of the same chitinase more weakly than allosamidin,promoted the chitinase production similarly to the case observed in the wild-type strain.Furthermore,by the experiment in an inorganic salt solution,it was shown that allosamidin could not induce the chitinase production without addition of N,N'-diacetylchitobiose.These results show that allosamidin can activate transcription of the chitinase gene through the two-component regulatory system in the presence of N,N'-diacetylchitobiose.