| Budget Amount *help |
¥2,470,000 (Direct Cost: ¥1,900,000、Indirect Cost: ¥570,000)
Fiscal Year 2015: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000)
Fiscal Year 2014: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000)
|
|---|
| Outline of Final Research Achievements |
Although stilbenes are a class of biologically active compounds distributed in a number of plant families, only Photorhabdus sp. produce stilbene compounds in microorganism kingdom. While plantal stilbenes are synthesized by a type III polyketide synthase, stilbene synthase, the bacterial stilbene scaffolds are generated by two enzymes, ketosynthase StlD and aromatase StlC. In this study, we characterized StlD and StlC in vitro enzyme reaction, and solved the crystal structures of StlD complex with substrate at 1.8 A resolution. The structural analysis and site-directed mutagenesis indicated that Glu154 acts as base-catalyst to activate β-keto acyl substrate and a water molecule. Surprisingly, StlD H302A mutant, one of catalytic residues in all ketosynthases, retains its enzyme activity. This suggested that StlD employs novel catalytic machinery for condensing two acyl substrates to produce cyclohexanedione scaffold.
|
