Related Experiment Video

Updated: Jul 9, 2026

Characterization at the Molecular Level using Robust Biochemical Approaches of a New Kinase Protein
11:23

Characterization at the Molecular Level using Robust Biochemical Approaches of a New Kinase Protein

Published on: June 30, 2019

Structural insights into the enzymatic mechanism of the pathogenic MAPK phosphothreonine lyase

Yongqun Zhu1, Hongtao Li, Chengzu Long

  • 1National Institute of Biological Sciences, Beijing, 102206, China.

Molecular Cell
|December 7, 2007
PubMed

Insights

Salmonella

Area of Science:

  • Molecular biology
  • Structural biology
  • Enzymology

Background:

  • The OspF family of phosphothreonine lyases, including SpvC from Salmonella, are pathogenic effectors.
  • These enzymes inactivate host mitogen-activated protein kinases (MAPKs) through beta-elimination.
  • Understanding the mechanism of MAPK inactivation is crucial for comprehending host-pathogen interactions.

Purpose of the Study:

  • To determine the crystal structures of SpvC and its complex with a phosphopeptide substrate.
  • To elucidate the mechanism of beta-elimination reaction catalyzed by phosphothreonine lyase.
  • To provide a structural understanding of MAPK inactivation by pathogenic effectors.

Main Methods:

  • X-ray crystallography to determine SpvC and SpvC-substrate complex structures.
  • Structure-based biochemical and enzymatic analyses.
  • Analysis of substrate recognition and active site interactions.

Main Results:

  • SpvC exhibits a unique alpha/beta fold with a disordered N-terminus for MAPK substrate docking.
  • Enzyme-substrate complex structure reveals phosphotyrosine recognition and phosphothreonine insertion into an arginine pocket.
  • Conformational flexibility of pT-X-pY suggests p38 as a likely physiological substrate.
  • A general acid/base mechanism for beta-elimination was proposed.

Conclusions:

  • The study provides a structural basis for MAPK inactivation by SpvC.
  • The proposed mechanism offers insights into beta-elimination reactions catalyzed by phosphothreonine lyases.
  • This work enhances understanding of host-pathogen interactions and may inspire new biological catalysts.

More Related Videos

Identification of Post-translational Modifications of Plant Protein Complexes10:07

Identification of Post-translational Modifications of Plant Protein Complexes

Published on: February 22, 2014

Assaying Protein Kinase Activity with Radiolabeled ATP08:05

Assaying Protein Kinase Activity with Radiolabeled ATP

Published on: May 26, 2017

Related Concept Videos

MAPK Signaling Cascades01:07

MAPK Signaling Cascades

Mitogen-activated protein kinase, or MAPK pathway, activates three sequential kinases to regulate cellular responses such as proliferation, differentiation, survival, and apoptosis. The canonical MAPK pathway starts with a mitogen or growth factor binding to an RTK. The activated RTKs stimulate Ras, which recruits Raf or MAP3 Kinase (MAPKKK), the first kinase of the MAPK signaling cascade. Raf further phosphorylates and activates MEK or MAP2 Kinases (MAPKK), which in turn phosphorylates MAP...
Protein Kinases and Phosphatases02:54

Protein Kinases and Phosphatases

Proteins undergo chemical modifications that trigger changes in the charge, structure, and conformation of the proteins. Phosphorylation, acetylation, glycosylation, nitrosylation, ubiquitination, lipidation, methylation, and proteolysis are various protein modifications that regulate protein activity. Such modifications are usually enzyme-driven.
Protein kinases
Many proteins in the cell are regulated by phosphorylation, the addition of a phosphate group. A family of enzymes called kinases...
Protein Kinases and Phosphatases02:54

Protein Kinases and Phosphatases

Proteins undergo chemical modifications that trigger changes in the charge, structure, and conformation of the proteins. Phosphorylation, acetylation, glycosylation, nitrosylation, ubiquitination, lipidation, methylation, and proteolysis are various protein modifications that regulate protein activity. Such modifications are usually enzyme-driven.
Protein kinases
Many proteins in the cell are regulated by phosphorylation, the addition of a phosphate group. A family of enzymes called kinases...
Phosphorylation01:02

Phosphorylation

The addition or removal of phosphate groups from proteins is the most common chemical modification that regulates cellular processes. These modifications can affect the structure, activity, stability, and localization of proteins within cells as well as their interactions with other proteins.
During phosphorylation, protein kinases transfer the terminal phosphate group of ATP to specific amino acid side chains of substrate proteins. Serine, threonine, and tyrosine are the most commonly...
Phosphorylation01:02

Phosphorylation

The addition or removal of phosphate groups from proteins is the most common chemical modification that regulates cellular processes. These modifications can affect the structure, activity, stability, and localization of proteins within cells as well as their interactions with other proteins.
During phosphorylation, protein kinases transfer the terminal phosphate group of ATP to specific amino acid side chains of substrate proteins. Serine, threonine, and tyrosine are the most commonly...
Amplifying Signals via Enzymatic Cascade01:22

Amplifying Signals via Enzymatic Cascade

When a ligand binds to a cell-surface receptor, the receptor's intracellular domain changes shape, which may either activate its enzyme function or allow its binding to other molecules. The initial signal is amplified by most signal transduction pathways. This means that a single ligand molecule can activate multiple molecules of a downstream target. Proteins that relay a signal are most commonly phosphorylated at one or more sites, activating or inactivating the protein. Kinases catalyze the...