AllR Controls the Expression of Streptomyces coelicolor Allantoin Pathway Genes

Abstract

cStreptomyces species are native inhabitants of soil, a natural environment where nutrients can be scarce and competition fierce. They have evolved ways to metabolize unusual nutrients, such as purines and its derivatives, which are highly abundant in soil. Catabolism of these uncommon carbon and nitrogen sources needs to be tightly regulated in response to nutrient availability and environmental stimulus. Recently, the allantoin degradation pathway was characterized in Streptomyces coelicolor. However, there are questions that remained unanswered, particularly regarding pathway regulation. Here, using a combination of proteomics and genetic approaches, we identified the negative regulator of the allantoin pathway, AllR. In vitro studies confirmed that AllR binds to the promoter regions of allantoin catabolic genes and determined the AllR DNA binding motif. In addition, effector studies showed that allantoic acid, and glyoxylate, to a lesser extent, inhibit the binding of AllR to the DNA. Inactivation of AllR repressor leads to the constitutive expression of the AllR regulated genes and intriguingly impairs actinorhodin and undecylprodigiosin production. Genetics and proteomics analysis revealed that among all genes from the allantoin pathway that are upregulated in the allR mutant, the hyi gene encoding a hydroxypyruvate isomerase (Hyi) is responsible of the impairment of antibiotic production.

Laboratory evolution reveals the metabolic and regulatory basis of ethylene glycol metabolism byPseudomonas putidaKT2440

“…These results raise the question: why are ethylene glycol or glyoxylate not the effectors that bind GclR to relieve repression of the downstream metabolic genes? Clues to the answer can be found in the genomic context of the gclR gene in P. putida KT2440, which, similarly to other organisms such as Escherichia coli , Streptomyces coelicolor and Bacillus subtilis (Cusa et al ., ; Schultz et al ., ; Rintoul et al ., ; Hasegawa et al ., ; Navone et al ., ), encodes multiple genes known or predicted to be involved in the metabolism of purines via the intermediates allantoin and glyoxylate (Fig. A,C).…”

The ARC2 response in Streptomcyes coelicolor requires the global regulatory genes afsR and afsS

“…coelicolor [49]. However, further research has indicated that the impairment of antibiotic production was an indirect effect of the imbalance in nitrogen metabolism [50].…”

Identification of Genes Regulated by the Antitermination Factor NasT during Denitrification in <i>Bradyrhizobium diazoefficiens</i>

“…The expression of a number of genes related to nitrogen acquisition, such as glc - hyi - glxR (allantoin degradation), paaIK (phenylacetate degradation), blr6443/45-6447 and bll0913 (LIV transport), nirA (assimilatory NO 2 − reductase), and glnK 2 (nitrogen regulatory protein PII), was down-regulated (Table 2 and Fig. 2) (1, 6, 13, 21, 36). The PII protein encoded by glnB was also down-regulated in the Δ nasT mutant of Paracoccus denitrificans (17).…”