Biochemical and structural insights into bacterial organelle form and biogenesis

J Biol Chem. 2008 May 23;283(21):14366-75. doi: 10.1074/jbc.M709214200. Epub 2008 Mar 10.

Abstract

Many heterotrophic bacteria have the ability to make polyhedral structures containing metabolic enzymes that are bounded by a unilamellar protein shell (metabolosomes or enterosomes). These bacterial organelles contain enzymes associated with a specific metabolic process (e.g. 1,2-propanediol or ethanolamine utilization). We show that the 21 gene regulon specifying the pdu organelle and propanediol utilization enzymes from Citrobacter freundii is fully functional when cloned in Escherichia coli, both producing metabolosomes and allowing propanediol utilization. Genetic manipulation of the level of specific shell proteins resulted in the formation of aberrantly shaped metabolosomes, providing evidence for their involvement as delimiting entities in the organelle. This is the first demonstration of complete recombinant metabolosome activity transferred in a single step and supports phylogenetic evidence that the pdu genes are readily horizontally transmissible. One of the predicted shell proteins (PduT) was found to have a novel Fe-S center formed between four protein subunits. The recombinant model will facilitate future experiments establishing the structure and assembly of these multiprotein assemblages and their fate when the specific metabolic function is no longer required.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacterial Proteins / genetics
  • Bacterial Proteins / metabolism
  • Biochemical Phenomena
  • Biochemistry
  • Cloning, Molecular
  • Electron Spin Resonance Spectroscopy
  • Escherichia coli / chemistry*
  • Escherichia coli / genetics
  • Escherichia coli / metabolism*
  • Escherichia coli / ultrastructure
  • Microscopy, Electron, Transmission
  • Molecular Sequence Data
  • Operon / genetics
  • Organelle Biogenesis*
  • Organelles / chemistry*
  • Organelles / metabolism*
  • Organelles / ultrastructure
  • Propanediol Dehydratase / metabolism
  • Propylene Glycol
  • Tandem Mass Spectrometry

Substances

  • Bacterial Proteins
  • Propylene Glycol
  • Propanediol Dehydratase

Associated data

  • GENBANK/AM498294