Lactococcus lactis YfiA is necessary and sufficient for ribosome dimerization

Authors

  • Pranav Puri,

    1. Department of Biochemisry, Groningen Biomolecular Sciences and Biotechnology Institute, Netherlands Proteomics Centre & Zernike Institute for Advance Materials, University of Groningen, Groningen, The Netherlands
    Search for more papers by this author
    • Equal contribution.
  • Thomas H. Eckhardt,

    1. Department of Molecular Genetics, Groningen Biomolecular Sciences and Biotechnology Institute, Netherlands Proteomics Centre & Zernike Institute for Advance Materials, University of Groningen, Groningen, The Netherlands
    Search for more papers by this author
    • Equal contribution.
  • Linda E. Franken,

    1. Department of Biophysical Chemistry, Groningen Biomolecular Sciences and Biotechnology Institute, Netherlands Proteomics Centre & Zernike Institute for Advance Materials, University of Groningen, Groningen, The Netherlands
    Search for more papers by this author
  • Fabrizia Fusetti,

    1. Department of Biochemisry, Groningen Biomolecular Sciences and Biotechnology Institute, Netherlands Proteomics Centre & Zernike Institute for Advance Materials, University of Groningen, Groningen, The Netherlands
    Search for more papers by this author
  • Marc C. A. Stuart,

    1. Department of Biophysical Chemistry, Groningen Biomolecular Sciences and Biotechnology Institute, Netherlands Proteomics Centre & Zernike Institute for Advance Materials, University of Groningen, Groningen, The Netherlands
    Search for more papers by this author
  • Egbert J. Boekema,

    1. Department of Biophysical Chemistry, Groningen Biomolecular Sciences and Biotechnology Institute, Netherlands Proteomics Centre & Zernike Institute for Advance Materials, University of Groningen, Groningen, The Netherlands
    Search for more papers by this author
  • Oscar P. Kuipers,

    1. Department of Molecular Genetics, Groningen Biomolecular Sciences and Biotechnology Institute, Netherlands Proteomics Centre & Zernike Institute for Advance Materials, University of Groningen, Groningen, The Netherlands
    Search for more papers by this author
  • Jan Kok,

    Corresponding author
    1. Department of Molecular Genetics, Groningen Biomolecular Sciences and Biotechnology Institute, Netherlands Proteomics Centre & Zernike Institute for Advance Materials, University of Groningen, Groningen, The Netherlands
    • For correspondence. E-mail b.poolman@rug.nl; Tel. (+31) 50 3634209; Fax (+31) 50 3634165. E-mail jan.kok@rug.nl; Tel. (+31) 50 3632111; Fax (+31) 50 3632348.

    Search for more papers by this author
  • Bert Poolman

    Corresponding author
    1. Department of Biochemisry, Groningen Biomolecular Sciences and Biotechnology Institute, Netherlands Proteomics Centre & Zernike Institute for Advance Materials, University of Groningen, Groningen, The Netherlands
    • For correspondence. E-mail b.poolman@rug.nl; Tel. (+31) 50 3634209; Fax (+31) 50 3634165. E-mail jan.kok@rug.nl; Tel. (+31) 50 3632111; Fax (+31) 50 3632348.

    Search for more papers by this author

Summary

Dimerization and inactivation of ribosomes in Escherichia coli is a two-step process that involves the binding of ribosome modulation factor (RMF) and hibernation promotion factor (HPF). Lactococcus lactis MG1363 expresses a protein, YfiALl, which associates with ribosomes in the stationary phase of growth and is responsible for dimerization of ribosomes. We show that full-length YfiALl is necessary and sufficient for ribosome dimerization in L. lactis but also functions heterologously in vitro with E. coli ribosomes. Deletion of the yfiA gene has no effect on the growth rate but diminishes the survival of L. lactis under energy-starving conditions. The N-terminal domain of YfiALl is homologous to HPF from E. coli, whereas the C-terminal domain has no counterpart in E. coli. By assembling ribosome dimers in vitro, we could dissect the roles of the N- and C-terminal domains of YfiALl. It is concluded that the dimerization and inactivation of ribosomes in L. lactis and E. coli differ in several cellular and molecular aspects. In addition, two-dimensional maps of dimeric ribosomes from L. lactis obtained by single particle electron microscopy show a marked structural difference in monomer association in comparison to the ribosome dimers in E. coli.

Ancillary