Structural and Functional Characterization of Rv0792c from Mycobacterium tuberculosis: Identifying Small Molecule...

Area of Science:

• Microbiology
• Structural Biology
• Molecular Biology

Background:

• Microbial pathogens utilize transcription factors to regulate gene expression for host tissue adaptation.
• The GntR family of transcription factors plays vital roles in prokaryotic biological processes, including stress adaptation and pathogenesis.

Purpose of the Study:

• To functionally and structurally characterize Rv0792c, a HutC homolog from Mycobacterium tuberculosis.
• To identify potential inhibitors of Rv0792c for therapeutic development against tuberculosis.

Main Methods:

• Functional characterization of Rv0792c using mutant strains and infection models.
• RNA sequencing to analyze gene expression regulated by Rv0792c.
• Solution small-angle X-ray scattering (SAXS) for structural modeling.
• Systematic evolution of ligands by exponential enrichment (SELEX) to identify DNA aptamers.
• Biochemical and biophysical assays for aptamer characterization.
• Identification of small-molecule inhibitors targeting Rv0792c.

Main Results:

• Rv0792c is essential for M. tuberculosis survival under oxidative stress and in guinea pig infection models.
• Rv0792c regulates genes involved in stress adaptation and virulence.
• SAXS confirmed the role of the C-terminal region in Rv0792c dimer formation.
• SELEX identified ssDNA aptamers that bind to Rv0792c, with specific residues identified for binding.
• I-OMe-Tyrphostin was identified as an inhibitor of Rv0792c's aptamer and DNA binding, reducing intracellular M. tuberculosis growth.

Conclusions:

• Rv0792c is a critical virulence factor in M. tuberculosis.
• The study provides a detailed shape-function characterization of a HutC family transcription factor.
• Identified aptamers and I-OMe-Tyrphostin represent potential tools and therapeutic leads for targeting M. tuberculosis.