Homology modeling and docking studies of Mycobacterium tuberculosis UDP- NAG enol pyruvyl transferase (Mtb-MurA) against drugs and derivatives of 5- sulfonoxyanthranilic acid derivatives

Abstract: The peptidoglycan synthesis in Mycobacterium tuberculosis is very essential for the survival of bacterium. Many antibiotics used in therapeutic settings, primarily glycopeptides and β-lactams, work by blocking the latter stages of peptidoglycan production. The cytoplasmic peptidoglycan precursor's early biosynthesis steps,
however, are not well-utilized as antibacterial targets because, with the exception of MurA, which is inhibited by fosfomycin, none of the enzymes involved in these steps are inhibited by synthetic chemicals or known antibiotics. In bacteria, every gene from murA to murF is necessary. Even though crystal structure of Mtb-MurA is available at
the Protein Data bank, few amino acid co-ordinates are missining . To understand the structure of Mtb- MurA protein, homology modeling was carried out with Modeller software. All the models were validated with PROCHECK and based on the quality of packing to 3D structure, one model selected for further docking process with inhibitors.
The inhibitor site was chosen based on the binding mode of Fosfomycin in the cavity of Mtb-MurA. The docking studies were carried out against various drugs and as well as derivatives of 5-sulfonoxyanthranilic acid derivatives. Based on docking energy and binding mode of derivatives, few compounds are predicted as potent inhibitors of Mur
A enzyme of peptidoglycan sysnthesis pathway. Based on our observations, we concluded that screened compounds may act as new leads for the design of Mtb MurA inhibitors.

Keywords: Mycobacterium tuberculosis, Mur A, Peptidoglycan synthesis, Homology
modeling, docking