AllR controls the expression of allantoin pathway genes in Streptomyces coelicolor

LAURA NAVONE; JUAN PABLO MACAGNO; CUAUHTÉMOC LICONA-CASSANI; ESTEBAN MARCELLIN; LARS K. NIELSEN; HUGO GRAMAJO; EDUARDO RODRIGUEZ

APPLIED AND ENVIRONMENTAL MICROBIOLOGY

AMER SOC MICROBIOLOGY

Lugar: Washington; Año: 2015 vol. 81 p. 6649 - 6659

0099-2240

Streptomyces 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, 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 S. coelicolor. However, there are questions that remained unanswered, particularly those 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 allantoin pathway that are up-regulated in the allR mutant, hyi gene encoding a hydroxypyruvate isomerase (Hyi) is responsible of the impairment of antibiotic production.