Table 1.
List of well-studied global regulators in Streptomyces
| Global regulator | Role | Effect on secondary metabolism | References |
|---|---|---|---|
| WblA* | Antibiotic downregulator | Negative | [13–15] |
| AdpA | Central transcriptional regulator; AdpA represses the transcription of wblA in S. coelicolor | Positive | [16] |
| DasR | Regulator of secondary metabolite gene expression in response to phosphorylated amino sugars | Negative | [17] |
| AtrA | Transcriptional activator of actinorhodin; antagonist to DasR | Positive | [18, 19] |
| Pfk* | Phosphofructokinase; key enzyme in glycolysis that controls metabolic fluxes affecting secondary metabolism | Negative | [20, 21] |
| KbpA-AfsKRS | Gene cascade linking phosphate and secondary metabolisms | Positive | [22] |
| PhoR-PhoP | Two component system regulating phosphate assimilation; overlaps with AfsKRS regulon | Negative | [23, 24] |
| AfsA-ArpA | Genes required for the biosynthesis and function of γ-butyrolactone A-factor in S. griseus | Positive | [25, 26] |
| CRP* | cAMP receptor protein; activates transcription of biosynthetic genes and controlling production of precursors; partially shared regulon with that of AfsKRS and PhoRP | Positive | [27] |
| AbsA1/2 | Two component system controlling antibiotic biosynthesis in S. coelicolor | Negative | [28] |
| AfsQ1/2 | Two component system controlling antibiotic biosynthesis in S. lividans | Positive | [29] |
| RelA | ppGpp synthetase gene; stringent response-induced antibiotic production | Positive | [30, 31] |
| RpoB | RNA polymerase subunit; mutations conferring rifampicin resistance and mimicking stringent response-induced secondary metabolism activation | Positive | [32] |
| RpsL | Encodes for S12 ribosomal protein; mutations conferring resistance to streptomycin promote secondary metabolism activation | Positive | [33] |
| BldA | Encodes the tRNA for the rare leucine TTA codon found in many secondary metabolite pathway-specific regulators | Positive | [34, 35] |
| SCO1712* | Antibiotic downregulator found in S. coelicolor | Negative | [36] |
Gene homologues have been found in many Streptomyces strains but not necessarily with the same impact on secondary metabolism
The S. albus gene homologues that are targeted in this study are indicated with an asterisk