creators_name: Chaudhary, Deepika creators_name: Singh, Avantika creators_name: Marzuki, Mardiana creators_name: Ghosh, Abhirupa creators_name: Kidwai, Saqib creators_name: Gosain, Tannu Priya creators_name: Chawla, Kiran creators_name: Gupta, Sonu Kumar creators_name: Agarwal, Nisheeth creators_name: Saha, Sudipto creators_name: Kumar, Yashwant creators_name: Thakur, Krishan Gopal creators_name: Singhal, Amit creators_name: Singh, Ramandeep type: article datestamp: 2022-12-15 10:11:59 lastmod: 2022-12-15 10:11:59 metadata_visibility: show title: Identification of small molecules targeting homoserine acetyl transferase from Mycobacterium tuberculosis and Staphylococcus aureus ispublished: pub subjects: QR note: The copyright of this article belongs to Nature abstract: There is an urgent need to validate new drug targets and identify small molecules that possess activity against both drug-resistant and drug-sensitive bacteria. The enzymes belonging to amino acid biosynthesis have been shown to be essential for growth in vitro, in vivo and have not been exploited much for the development of anti-tubercular agents. Here, we have identified small molecule inhibitors targeting homoserine acetyl transferase (HSAT, MetX, Rv3341) from M. tuberculosis. MetX catalyses the first committed step in L-methionine and S-adenosyl methionine biosynthesis resulting in the formation of O-acetyl-homoserine. Using CRISPRi approach, we demonstrate that conditional repression of metX resulted in inhibition of M. tuberculosis growth in vitro. We have determined steady state kinetic parameters for the acetylation of L-homoserine by Rv3341. We show that the recombinant enzyme followed Michaelis–Menten kinetics and utilizes both acetyl-CoA and propionyl-CoA as acyl-donors. High-throughput screening of a 2443 compound library resulted in identification of small molecule inhibitors against MetX enzyme from M. tuberculosis. The identified lead compounds inhibited Rv3341 enzymatic activity in a dose dependent manner and were also active against HSAT homolog from S. aureus. Molecular docking of the identified primary hits predicted residues that are essential for their binding in HSAT homologs from M. tuberculosis and S. aureus. ThermoFluor assay demonstrated direct binding of the identified primary hits with HSAT proteins. Few of the identified small molecules were able to inhibit growth of M. tuberculosis and S. aureus in liquid cultures. Taken together, our findings validated HSAT as an attractive target for development of new broad-spectrum anti-bacterial agents that should be effective against drug-resistant bacteria. date: 2022-08-13 date_type: published publication: SCIENTIFIC REPORTS volume: 12 number: 1 publisher: Nature refereed: TRUE official_url: https://www.nature.com/articles/s41598-022-16468-w#:~:text=Here%2C%20we%20have%20identified%20small,of%20O%2Dacetyl%2Dhomoserine. citation: Chaudhary, Deepika and Singh, Avantika and Marzuki, Mardiana and Ghosh, Abhirupa and Kidwai, Saqib and Gosain, Tannu Priya and Chawla, Kiran and Gupta, Sonu Kumar and Agarwal, Nisheeth and Saha, Sudipto and Kumar, Yashwant and Thakur, Krishan Gopal and Singhal, Amit and Singh, Ramandeep (2022) Identification of small molecules targeting homoserine acetyl transferase from Mycobacterium tuberculosis and Staphylococcus aureus. SCIENTIFIC REPORTS, 12 (1).