Spinosyn-producing polyketide synthases
The invention provides, biologically active spinosyns, hybrid spinosyn polyketide synthases capable of functioning in Saccharopolyspora spinosa to produce the spinosyns, and methods of controlling insects using the spinosyns.
1. A hybrid spinosyn polyketide synthase that is capable of functioning in Saccharopolyspora spinosa to produce a biologically active 16-ethyl spinosyn compound, said hybrid polyketide synthase comprising a spinosyn polyketide synthase selected from the group consisting of an endogenous S. spinosa spnA, spnB, spnC, spnD, and spnE, wherein the AT domain of module 3 in the spinosyn polyketide synthase has been replaced with an AT domain that normally incorporates ethyl malonyl-CoA.
2. The hybrid spinosyn polyketide synthase of claim 1 wherein the AT domain that normally incorporates ethyl malonyl-CoA is the AT domain of module 5 in the tylosin PKS.
3. The hybrid spinosyn polyketide synthase of claim 2 wherein said AT domain that normally incorporates ethyl malonyl-CoA is encoded by of SEQ ID NO:26.
4. A Saccharopolyspora spinosa strain comprising the hybrid spinosyin polyketide synthase of claim 1 that has been transformed with DNA encoding the Streptomyces cinnamonensis crotonyl-CoA reductase.