Related Experiment Video
Updated: Nov 22, 2025
X-Ray Crystallography to Study the Oligomeric State Transition of the Thermotoga maritima M42 Aminopeptidase TmPep1050
Published on: May 13, 2020
Mycobacterium tuberculosis puromycin hydrolase displays a prolyl oligopeptidase fold and an acyl aminopeptidase
YuanHao Zhao1, Qiaoli Feng1, Xiao Zhou2
1Department of Biological Sciences, School of Science, Xi'an Jiaotong-Liverpool University, Suzhou, Jiangsu, China.
Abstract:
Puromycin-hydrolizing peptidases have been described as members of the prolyl oligopeptidase peptidase family. These enzymes are present across all domains of life but still little is known of the homologs found in the pathogenic bacterium Mycobacterium tuberculosis. The crystal structure of a M. tuberculosis puromycin hydrolase peptidase has been determined at 3 Angstrom resolution, revealing a conserved prolyl oligopeptidase fold, defined by α/β-hydrolase and β-propeller domains with two distinctive loops that occlude access of large substrates to the active site. The enzyme displayed amino peptidase activity with a substrate specificity preference for hydrophobic residues in the decreasing order of phenylalanine, leucine, alanine and proline. The enzyme's active site is lined by residues Glu564 for the coordination of the substrates amino terminal moiety and His561, Val608, Tyr78, Trp306, Phe563 and Ty567 for the accommodation of hydrophobic substrates. The availability of a crystal structure for puromycin hydrolase of M. tuberculosis shall facilitate the development of inhibitors with therapeutic applications.
Insights
Researchers determined the crystal structure of Mycobacterium tuberculosis puromycin hydrolase. This enzyme shows amino peptidase activity, preferring hydrophobic residues, and its structure aids in developing new therapeutic inhibitors.
Area of Science:
- Biochemistry
- Structural Biology
- Microbiology
Background:
- Puromycin-hydrolizing peptidases belong to the prolyl oligopeptidase family, found across all life domains.
- Homologs in Mycobacterium tuberculosis are poorly understood, despite their potential relevance.
Purpose of the Study:
- To elucidate the structural and functional characteristics of a puromycin-hydrolizing peptidase from Mycobacterium tuberculosis.
- To provide a structural basis for understanding enzyme activity and for developing targeted inhibitors.
Main Methods:
- X-ray crystallography was used to determine the enzyme's structure at 3 Angstrom resolution.
- Enzyme activity assays were performed to assess substrate specificity.
Main Results:
- The crystal structure revealed a conserved prolyl oligopeptidase fold with alpha/beta-hydrolase and beta-propeller domains.
- Distinctive loops were identified that limit access for larger substrates to the active site.
- The enzyme exhibited amino peptidase activity, with a preference for hydrophobic residues like phenylalanine and leucine.
Conclusions:
- The determined crystal structure of Mycobacterium tuberculosis puromycin hydrolase provides crucial insights into its fold and active site.
- Understanding the enzyme's substrate specificity and structural features facilitates the rational design of therapeutic inhibitors.
Related Concept Videos
01:13The Proteasome
In this pathway, the target proteins are first tagged with small proteins called ubiquitin. This involves participation of a series of enzymes including— E1 (ubiquitin-activating enzyme), E2 (ubiquitin-conjugating enzyme), and E3...
01:17The Proteasome Structure
The proteasome is an...