Promoter characterization of relZ-bifunctional (pp)pGpp synthetase in mycobacteria
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View abstract on PubMed
Summary
This summary is machine-generated.Mycobacteria survival relies on (p)ppGpp, synthesized by Rel and the newly discovered RelZ enzyme. RelZ expression is constitutive, induced by carbon starvation, and regulated by SigA/SigB, with Rel influencing its activity.
Area Of Science
- Microbiology
- Molecular Biology
- Biochemistry
Background
- The second messenger guanosine 3',5'-bis(diphosphate)/guanosine tetraphosphate ((p)ppGpp) is vital for mycobacterial survival under stress.
- Deletion of the primary synthetase Rel did not abolish (p)ppGpp levels, leading to the discovery of the bifunctional enzyme RelZ.
Purpose Of The Study
- To investigate the expression conditions and regulation of the novel RelZ enzyme in mycobacteria.
- To compare the transcriptional regulation of relZ with the rel promoter.
- To understand the interplay between Rel and RelZ in (p)ppGpp synthesis.
Main Methods
- Promoter activity assays for relZ and rel under various growth conditions.
- Comparison of promoter activity in wild-type and rel-knockout strains.
- Analysis of the role of SigA and SigB sigma factors in relZ regulation.
Main Results
- RelZ exhibits constitutive promoter activity, weaker than rel, and is induced by carbon starvation.
- RelZ promoter activity is compromised in the rel-knockout strain during stationary phase.
- SigA and SigB sigma factors dynamically regulate relZ promoter activity across different growth phases.
Conclusions
- RelZ plays a significant role in (p)ppGpp synthesis and is subject to complex transcriptional regulation.
- Understanding RelZ's regulatory network, influenced by sigma factors and Rel, is crucial for developing targeted mycobacterial interventions.
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