Table 2.
Identified homologs of AfsR involved in the biosynthesis of secondary metabolites in Streptomyces species.
| Regulators | Strains | Secondary metabolites | BCG type | Effect | Increased yield | References |
|---|---|---|---|---|---|---|
| AfsR | S. coelicolor A3(2) | Undecylprodigiosin | Type I PKS | Activator | / | Liu et al. (2013) |
| Calcium-dependent antibiotic | NRPS | |||||
| Actinorhodin | Type II PKS | |||||
| AfsR-sv | S. venezuelae ATCC 15439 | Pikromycin | Type I PKS | Activator | / | Maharjan et al. (2009) |
| AfsR-sp | S. peucetius ATCC 27952 | Doxorubicin | Type II PKS | Activator | 400% doxorubicin 260% actinorhodin* 150% clavulanic acid* 260% pikromycin* |
Parajuli et al. (2005) |
| AfsR | S. acidiscabies ATCC 49003 | WS5995B | Type II PKS | Activator | / | Kim et al. (2012) |
| Thaxtomin | NRPS | |||||
| AfsR | S. pristinaespiralis Pr11 | Pristinamycin I | NRPS | Repressor | / | Jin et al. (2021) |
| Pristinamycin II | NRPS/PKS | Activator | ||||
| AfsR | S. roseosporus NRRL11379 | Daptomycin | NRPS | Activator | 120% | Yan et al. (2020) |
| AfsR | S. lomondensis S015 | Lomofungin | NRPS | Activator | 250% | Wang et al. (2015) |
The AfsR of S. venezuelae is named AfsR-sv and regulates pikromycin biosynthesis. The AfsR of S. peucetius is named AfsR-sp. and regulates doxorubicin biosynthesis.
*Overexpression of afsR-sp. in S. lividans improved the production of actinorhodin. Overexpression of afsR-sp. in S. clavuligerus led to increased clavulanic acid production. Overexpression of afsR-sp. in S. venezuelae resulted in enhanced production of pikromycin.