Sharma_2023_ACS.Infect.Dis__

Reference

Title : Structural and Functional Characterization of Mycobacterium tuberculosis Homoserine Transacetylase - Sharma_2023_ACS.Infect.Dis__
Author(s) : Sharma S , Jayasinghe YP , Mishra NK , Orimoloye MO , Wong TY , Dalluge JJ , Ronning DR , Aldrich CC
Ref : ACS Infect Dis , : , 2023
Abstract :

Mycobacterium tuberculosis (Mtb) lacking functional homoserine transacetylase (HTA) is compromised in methionine biosynthesis, protein synthesis, and in the activity of multiple essential S-adenosyl-l-methionine-dependent enzymes. Additionally, deficient mutants are further disarmed by the toxic accumulation of lysine due to a redirection of the metabolic flux toward the lysine biosynthetic pathway. Studies with deletion mutants and crystallographic studies of the apoenzyme have, respectively, validated Mtb HTA as an essential enzyme and revealed a ligandable binding site. Seeking a mechanistic characterization of this enzyme, we report crucial structural details and comprehensive functional characterization of Mtb HTA. Crystallographic and mass spectral observation of the acetylated HTA intermediate and initial velocity studies were consistent with a ping-pong kinetic mechanism. Wild-type HTA and its site-directed mutants were kinetically characterized with a panel of natural and alternative substrates to understand substrate specificity and identify critical residues for catalysis. Titration experiments using fluorescence quenching showed that both substratesacetyl-CoA and l-homoserineengage in a strong and weak binding interaction with HTA. Additionally, substrate inhibition by acetyl-CoA and product inhibition by CoA and O-acetyl-l-homoserine were proposed to form the basis of a feedback regulation mechanism. By furnishing key mechanistic and structural information, these studies provide a foundation for structure-based design efforts around this attractive Mtb target.

PubMedSearch : Sharma_2023_ACS.Infect.Dis__
PubMedID: 36753622
Gene_locus related to this paper: myctu-metx

Related information

Gene_locus myctu-metx
Structure myctu-metx    7YRT

Citations formats

Sharma S, Jayasinghe YP, Mishra NK, Orimoloye MO, Wong TY, Dalluge JJ, Ronning DR, Aldrich CC (2023)
Structural and Functional Characterization of Mycobacterium tuberculosis Homoserine Transacetylase
ACS Infect Dis :

Sharma S, Jayasinghe YP, Mishra NK, Orimoloye MO, Wong TY, Dalluge JJ, Ronning DR, Aldrich CC (2023)
ACS Infect Dis :