Table 1 Strains and plasmids used in this study
Strains/plasmids | Characteristics | Source |
|---|---|---|
E. coli | ||
 DH5α | General cloning host for plasmid manipulation | Lab collection |
 BL21(DE3) | The host of protein overexpression | Lab collection |
 ET12567/pUZ8002 | Strain for conjugal transfer, with pUZ8002 helper plasmids, ChlR, KanR | Lab collection |
 BL21/pET28a-MtrA | E. coli BL21(DE3), with MtrA expression vector pET28a-MtrA, KanR | This work |
S. avermectin | ||
 ATCC 31267 | Wild-type avermectin producer | Lab collection |
 OmtrA | The wild-type strain with mtrA overexpression vector pIBOmtrA, AprR | This work |
 DmtrA | The wild-type strain with mtrA deletion vector pKCDmtrA, AprR | This work |
 C-DmtrA | The DmtrA strain with mtrA complemented vector pSECmtrA, AprR | This work |
Plasmids | ||
 pSET152 | Integrative E. coli-streptomyces shuttle vector, AprR | Lab collection |
 pIB139 | pSET152 derivative carrying Streptomyces strong constitutive promoter ermE*p, AprR | Lab collection |
 pKCcas9dO | Temperature-sensitive replicon pSG5, AprR | Lab collection |
 pIBOmtrA | mtrA overexpression vector based on pIB139 | This work |
 pKCDmtrA | mtrA deletion vector based on pKCcas9dO | This work |
 pSECmtrA | mtrA complemented vector based on pSET152 | This work |
 pET-28a ( +) | Vector for protein expression in E. coli, N-terminal His6-tag, KanR | Novagen |