Novel Glutamate–Putrescine Ligase Activity in Haloferax mediterranei: A New Function for glnA-2 Gene

Rodríguez-Herrero, Verónica; Peris, Arnau; Camacho, Mónica; Bautista, Vanesa; Esclapez, Julia; Bonete, Marı́a José

doi:10.3390/biom11081156

Cited by 4 publications

(5 citation statements)

References 64 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Furthermore, the enzymatic function of GlnA2 demonstrated in this work is similar to the function of GlnA2 in the halophilic archaea Haloferax mediterranei . It has been demonstrated that in this organism GlnA2 is not a GS but a glutamate-putrescine ligase involved in polyamine metabolism [ 28 ].…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

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

Krysenko

Okoniewski

Nentwich

et al. 2022

IJMS

View full text Add to dashboard Cite

Streptomyces coelicolor 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 S. coelicolor to survive under high toxic polyamine concentrations. GlnA2 is a gamma-glutamylpolyamine synthetase, an enzyme catalyzing the first step in polyamine catabolism. The role of GlnA2 was confirmed in phenotypical studies with a glnA2 deletion mutant as well as in transcriptional and biochemical analyses. Among all GS-like enzymes in S. coelicolor, GlnA2 possesses the highest specificity towards short-chain polyamines (putrescine and cadaverine), while its functional homolog GlnA3 (SCO6962) prefers long-chain polyamines (spermidine and spermine) and GlnA4 (SCO1613) accepts only monoamines. The genome-wide RNAseq analysis in the presence of the polyamines putrescine, cadaverine, spermidine, or spermine revealed indication of the occurrence of different routes for polyamine catabolism in S. coelicolor involving GlnA2 and GlnA3. Furthermore, GlnA2 and GlnA3 are differently regulated. From our results, we can propose a complemented model of polyamine catabolism in S. coelicolor, which involves the gamma-glutamylation pathway as well as other alternative utilization pathways.

show abstract

Section: Discussionmentioning

confidence: 99%

“…However, the primary enzymatic function of glnA2 in M. bovis and S. coelicolor remained unknown. Recently, GlnA2 has been described as a putrescine-glutamate ligase (HFX_01688) in the halophilic archaea Haloferax mediterranei , suggesting a role of GlnA2 in polyamine metabolism [ 28 ].…”

Section: Introductionmentioning

confidence: 99%

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

Krysenko

Okoniewski

Nentwich

et al. 2022

IJMS

View full text Add to dashboard Cite

show abstract

“…These genes show a high homology with glutamine synthetase (GlnA), but it has been proposed that their role was different ( 66 ). Although the role of GlnA3 has not yet been described, GlnA2 is known to have glutamate–putrescine ligase activity and could be responsible for the growth of H. mediterranei in the presence of putrescine as the sole source of nitrogen and carbon ( 67 ). The transcriptional repression of both genes does not appear to be related to the decrease in ammonium concentration, as previous analyses of H. mediterranei ’s response to ammonium starvation did not reveal a reduction in the transcription of glnaA 2 or glnA 3.…”

Section: Resultsmentioning

confidence: 99%

Transcriptomic profiling of haloarchaeal denitrification through RNA-Seq analysis

Miralles-Robledillo,

Martínez-Espinosa,

Pire

2024

Appl Environ Microbiol

View full text Add to dashboard Cite

Denitrification, a crucial biochemical pathway prevalent among haloarchaea in hypersaline ecosystems, has garnered considerable attention in recent years due to its ecological implications. Nevertheless, the underlying molecular mechanisms and genetic regulation governing this respiration/detoxification process in haloarchaea remain largely unexplored. In this study, RNA-sequencing was used to compare the transcriptomes of the haloarchaeon Haloferax mediterranei under oxic and denitrifying conditions, shedding light on the intricate metabolic alterations occurring within the cell, such as the accurate control of the metal homeostasis. Furthermore, the investigation identifies several genes encoding transcriptional regulators and potential accessory proteins with putative roles in denitrification. Among these are bacterioopsin-like transcriptional activators, proteins harboring a domain of unknown function (DUF2249), and cyanoglobin. In addition, the study delves into the genetic regulation of denitrification, finding a regulatory motif within promoter regions that activates numerous denitrification-related genes. This research serves as a starting point for future molecular biology studies in haloarchaea, offering a promising avenue to unravel the intricate mechanisms governing haloarchaeal denitrification, a pathway of paramount ecological importance. IMPORTANCE Denitrification, a fundamental process within the nitrogen cycle, has been subject to extensive investigation due to its close association with anthropogenic activities, and its contribution to the global warming issue, mainly through the release of N 2 O emissions. Although our comprehension of denitrification and its implications is generally well established, most studies have been conducted in non-extreme environments with mesophilic microorganisms. Consequently, there is a significant knowledge gap concerning extremophilic denitrifiers, particularly those inhabiting hypersaline environments. The significance of this research was to delve into the process of haloarchaeal denitrification, utilizing the complete denitrifier haloarchaeon Haloferax mediterranei as a model organism. This research led to the analysis of the metabolic state of this microorganism under denitrifying conditions and the identification of regulatory signals and genes encoding proteins potentially involved in this pathway, serving as a valuable resource for future molecular studies.

show abstract

“…For example, Mycobacterium tuberculosis expresses three GS‐like enzymes (GlnA2 Mt , GlnA3 Mt , GlnA4 Mt ) [1] in addition to the archetypal GS (GlnA1 Mt or MtGS) and Pseudomonas aeruginosa contains seven additional GS‐like enzymes (PauA1‐7) [2] . Likewise, the actinobacterium Streptomyces coelicolor has three GS‐like enzymes (GlnA2 Sc , GlnA3 Sc , GlnA4 Sc ), [3] and the halophilic archaea Haloferax mediterranei harbours two GS‐like enzymes (GlnA2 Hm , GlnA3 Hm ) [4] . GlnA3 Sc and GlnA2 Hm were recently shown to be putative glutamate polyamine ligases.…”

Section: Introductionmentioning

confidence: 99%

“… [2] Likewise, the actinobacterium Streptomyces coelicolor has three GS‐like enzymes (GlnA2 Sc , GlnA3 Sc , GlnA4 Sc ), [3] and the halophilic archaea Haloferax mediterranei harbours two GS‐like enzymes (GlnA2 Hm , GlnA3 Hm ). [4] GlnA3 Sc and GlnA2 Hm were recently shown to be putative glutamate polyamine ligases. We recently identified GlnA4 from Streptomyces coelicolor to be an ATP‐dependent γ‐glutamylethanolamine synthetase with a putative mechanism similar to GS (Scheme 1 c).…”

Section: Introductionmentioning

confidence: 99%

Mechanism‐Based Design of the First GlnA4‐Specific Inhibitors

et al. 2022

View full text Add to dashboard Cite

γ-Glutamylamine synthetases are an important class of enzymes that play a key role in glutamate-based metabolism. Methionine sulfoximine (MSO) is a well-established inhibitor for the archetypal glutamine synthetase (GS) but inhibitors for most GS-like enzymes are unknown. Assuming a conserved catalytic mechanism for GS and GS-like enzymes, we explored if subtype-selective inhibitors can be obtained by merging MSO with the cognate substrates of the respective GS-like enzymes. Using GlnA4 Sc from Streptomyces coelicolor, an enzyme recently shown to produce γ-glutamylethanolamine, we demonstrate that MSO can be reengineered in a straightforward fashion into potent and selective GlnA4 Sc inhibitors. Linkage chemistry as well as linker length between the MSO moiety and the terminal hydroxyl group derived from ethanolamine were in agreement with the postulated phosphorylated catalytic intermediate. The best GlnA4 inhibitor 7 b potently blocked S. coelicolor growth in the presence of ethanolamine as the sole nitrogen source. Our results provide the first GlnA4 Sc -specific inhibitors and suggest a general strategy to develop mechanism-based inhibitors for GSlike enzymes.

show abstract

Novel Glutamate–Putrescine Ligase Activity in Haloferax mediterranei: A New Function for glnA-2 Gene

Cited by 4 publications

References 64 publications

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

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

Transcriptomic profiling of haloarchaeal denitrification through RNA-Seq analysis

Mechanism‐Based Design of the First GlnA4‐Specific Inhibitors

Contact Info

Product

Resources

About