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FlaK of the archaeon Methanococcus maripaludis possesses preflagellin peptidase activity

Sonia L Bardy1, Ken F Jarrell

  • 1Department of Microbiology and Immunology, Queen's University, K7L 3N6, Kingston, ON, Canada.

FEMS Microbiology Letters
|April 6, 2002
PubMed

Insights

Researchers identified FlaK as the enzyme responsible for cleaving archaeal preflagellins. This discovery marks the first identification of a preflagellin peptidase, advancing our understanding of archaeal flagellation mechanisms.

Area of Science:

  • Microbiology
  • Molecular Biology
  • Biochemistry

Background:

  • Archaeal flagellins are synthesized as preflagellins with a cleavable leader peptide.
  • Preflagellin peptidase activity was known in methanogens, but the responsible enzyme remained unidentified.

Purpose of the Study:

  • To identify the enzyme responsible for archaeal preflagellin processing.
  • To characterize the function of the FlaK gene in archaeal flagellation.

Main Methods:

  • In vitro preflagellin peptidase assay using Escherichia coli membranes.
  • Overexpression of Methanococcus voltae preflagellin FlaB2 as substrate and Methanococcus maripaludis FlaK as enzyme.
  • Immunoblotting with anti-FlaB2 antibody to detect cleavage products.

Main Results:

  • Methanococcus maripaludis FlaK demonstrated preflagellin peptidase activity in vitro.
  • Cleavage was confirmed by detecting a faster migrating species using immunoblotting.
  • Enzyme activity required detergent and was abolished by heat treatment (95°C).

Conclusions:

  • FlaK is identified as the archaeal preflagellin peptidase.
  • This is the first functional assignment for a gene involved in archaeal flagellation, excluding flagellins themselves.

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