A Second Gamma-Glutamylpolyamine Synthetase, GlnA2, Is Involved in Polyamine Catabolism in .

is a soil bacterium living in a habitat with very changeable nutrient availability. This organism possesses a complex nitrogen metabolism and is able to utilize the polyamines putrescine, cadaverine, spermidine, and spermine and the monoamine ethanolamine. We demonstrated that GlnA2 (SCO2241) facilitates to survive under high toxic polyamine concentrations.

Bacterial flavoprotein monooxygenase YxeK salvages toxic S-(2-succino)-adducts via oxygenolytic C-S bond cleavage.

Thiol-containing nucleophiles such as cysteine react spontaneously with the citric acid cycle intermediate fumarate to form S-(2-succino)-adducts. In Bacillus subtilis, a salvaging pathway encoded by the yxe operon has recently been identified for the detoxification and exploitation of these compounds as sulfur sources. This route involves acetylation of S-(2-succino)cysteine to N-acetyl-2-succinocysteine, which is presumably converted to oxaloacetate and N-acetylcysteine, before a final deacetylation step affords cysteine.

Poly- and Monoamine Metabolism in Streptomyces coelicolor: The New Role of Glutamine Synthetase-Like Enzymes in the Survival under Environmental Stress.

Soil bacteria from the genus Streptomyces, phylum Actinobacteria, feature a complex metabolism and diverse adaptations to environmental stress. These characteristics are consequences of variable nutrition availability in the soil and allow survival under changing nitrogen conditions. Streptomyces coelicolor is a model organism for Actinobacteria and is able to use nitrogen from a variety of sources including unusual compounds originating from the decomposition of dead plant and animal material, such as polyamines or monoamines (like ethanolamine).

The devil is in the details: The chemical basis and mechanistic versatility of flavoprotein monooxygenases.

The ubiquitous flavoenzymes commonly catalyze redox chemistry such as the monooxygenation of organic substrates and are both widely utilized in nature (e.g., in primary and secondary metabolism) and of significant industrial interest.

Aminoperoxide adducts expand the catalytic repertoire of flavin monooxygenases.

One of the hallmark reactions catalyzed by flavin-dependent enzymes is the incorporation of an oxygen atom derived from dioxygen into organic substrates. For many decades, these flavin monooxygenases were assumed to use exclusively the flavin-C4a-(hydro)peroxide as their oxygen-transferring intermediate. We demonstrate that flavoenzymes may instead employ a flavin-N5-peroxide as a soft α-nucleophile for catalysis, which enables chemistry not accessible to canonical monooxygenases.

Initial Metabolic Step of a Novel Ethanolamine Utilization Pathway and Its Regulation in M145.

is a Gram-positive soil bacterium with a high metabolic and adaptive potential that is able to utilize a variety of nitrogen sources. However, little is known about the utilization of the alternative nitrogen source ethanolamine. Our study revealed that can utilize ethanolamine as a sole nitrogen or carbon (/) source, although it grows poorly on this nitrogen source due to the absence of a specific ethanolamine permease.

Gamma-Glutamylpolyamine Synthetase GlnA3 Is Involved in the First Step of Polyamine Degradation Pathway in M145.

M145 was shown to be able to grow in the presence of high concentrations of polyamines, such as putrescine, cadaverine, spermidine, or spermine, as a sole nitrogen source. However, hardly anything is known about polyamine utilization and its regulation in streptomycetes. In this study, we demonstrated that only one of the three proteins annotated as glutamine synthetase-like protein, GlnA3 (SCO6962), was involved in the catabolism of polyamines.

Post-translational Serine/Threonine Phosphorylation and Lysine Acetylation: A Novel Regulatory Aspect of the Global Nitrogen Response Regulator GlnR in S. coelicolor M145.

Soil-dwelling Streptomyces bacteria such as S.coelicolor have to constantly adapt to the nitrogen (N) availability in their habitat. Thus, strict transcriptional and post-translational control of the N-assimilation is fundamental for survival of this species.