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Updated: Aug 7, 2026

A Mass Spectrometry-Based Approach to Identify Phosphoprotein Phosphatases and their Interactors
10:17

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Regulatory protein phosphorylation in Mycoplasma pneumoniae. A PP2C-type phosphatase serves to dephosphorylate

Sven Halbedel1, Julia Busse, Sebastian R Schmidl

  • 1Department of General Microbiology, Institute of Microbiology and Genetics, Georg-August University, D-37077 Göttingen, Germany.

The Journal of Biological Chemistry
|July 22, 2006
PubMed

Insights

In Mycoplasma pneumoniae, the HPr phosphocarrier protein

Area of Science:

  • Microbiology
  • Molecular Biology
  • Biochemistry

Background:

  • The phosphotransferase system (PTS) in Mycoplasma pneumoniae involves the phosphorylation of the HPr protein.
  • HPr phosphorylation is regulated by HPr kinase/phosphorylase in an ATP-dependent manner, particularly in the presence of glycerol.

Purpose of the Study:

  • To investigate the role of HPr kinase/phosphorylase in M. pneumoniae.
  • To identify the enzyme responsible for dephosphorylating serine-phosphorylated HPr (HPr(Ser-P)).

Main Methods:

  • Construction and analysis of an M. pneumoniae hprK mutant.
  • Genome sequence analysis to identify potential phosphatase genes.
  • Purification and biochemical characterization of the PrpC protein.
  • Isolation and analysis of a prpC mutant strain.

Main Results:

  • The hprK mutant lacked HPr kinase activity but retained HPr(Ser-P) phosphatase activity.
  • A gene (prpC) encoding a PP2C family protein serine/threonine phosphatase was identified.
  • Purified PrpC demonstrated HPr(Ser-P) dephosphorylation activity.
  • The prpC mutant showed impaired HPr(Ser-P) dephosphorylation.

Conclusions:

  • PrpC is the primary enzyme responsible for HPr(Ser-P) dephosphorylation in M. pneumoniae.
  • PrpC plays a crucial role in regulating HPr phosphorylation state.
  • This regulation impacts diverse cellular functions controlled by different HPr forms.

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