Suzuki Shigeo, Nakanishi Eiyu, Ohira Tsuyoshi, Kawachi Ryu, Ohnishi Yasuo, Horinouchi Sueharu, Nagasawa Hiromichi, Sakuda Shohei
Department of Applied Biological Chemistry, The University of Tokyo, Bunkyo-ku, Tokyo 113-8657, Japan.
J Antibiot (Tokyo). 2006 Jul;59(7):410-7. doi: 10.1038/ja.2006.58.
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.
在几丁质酶抑制剂阿洛沙米定的产生菌链霉菌属AJ9463中，阿洛沙米定能显著提高几丁质酶的产量，该几丁质酶主要分泌到几丁质培养基的培养液中。为阐明阿洛沙米定对几丁质酶产生的调控机制，对几丁质酶基因5'上游区域存在的构成双组分调控系统的蛋白质编码基因进行了破坏实验。在获得的破坏突变体中，阿洛沙米定不能促进几丁质酶的产生，但N，N'-二乙酰壳二糖（其促进同一几丁质酶产生的作用也比阿洛沙米定弱）能像在野生型菌株中观察到的情况一样促进几丁质酶的产生。此外，通过在无机盐溶液中的实验表明，不添加N，N'-二乙酰壳二糖时阿洛沙米定不能诱导几丁质酶的产生。这些结果表明，在存在N，N'-二乙酰壳二糖的情况下，阿洛沙米定可通过双组分调控系统激活几丁质酶基因的转录。
