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L actococcus lactis YfiA is necessary and sufficient for ribosome dimerization
Author(s) -
Puri Pranav,
Eckhardt Thomas H.,
Franken Linda E.,
Fusetti Fabrizia,
Stuart Marc C. A.,
Boekema Egbert J.,
Kuipers Oscar P.,
Kok Jan,
Poolman Bert
Publication year - 2014
Publication title -
molecular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 247
eISSN - 1365-2958
pISSN - 0950-382X
DOI - 10.1111/mmi.12468
Subject(s) - ribosome , biology , escherichia coli , eukaryotic ribosome , biochemistry , microbiology and biotechnology , gene , rna
Summary Dimerization and inactivation of ribosomes in E scherichia coli is a two‐step process that involves the binding of ribosome modulation factor ( RMF ) and hibernation promotion factor ( HPF ). L actococcus lactis MG 1363 expresses a protein, YfiA L l , which associates with ribosomes in the stationary phase of growth and is responsible for dimerization of ribosomes. We show that full‐length YfiA L l 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 YfiA L l 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 YfiA L l . 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 .