|
García-Marcos A, Morreale A, Guarinos E, Briones E, Remacha M,
Ortiz AR, Ballesta JP. Nucleic Acids Res. 2007;35(21):7109-17.
In vivo assembling of bacterial ribosomal protein L11 into
yeast ribosomes makes the particles sensitive to the prokaryotic
specific antibiotic thiostrepton.
Centro de Biología Molecular Severo Ochoa, Universidad
Autónoma de Madrid and Consejo Superior de investigaciones
Científicas, Cantoblanco, Madrid 28049, Spain.
Eukaryotic ribosomal stalk protein L12 and its bacterial
orthologue L11 play a central role on ribosomal conformational
changes during translocation. Deletion of the two genes encoding
L12 in Saccharomyces cerevisiae resulted in a very slow-growth
phenotype. Gene RPL12B, but not the RPL12A, cloned in
centromeric plasmids fully restored control protein level and
the growth rate when expressed in a L12-deprived strain. The
same strain has been transformed to express Escherichia coli
protein EcL11 under the control of yeast RPL12B promoter. The
bacterial protein has been found in similar amounts in washed
ribosomes from the transformed yeast strain and from control E.
coli cells, however, EcL11 was unable to restore the defective
acidic protein stalk composition caused by the absence of ScL12
in the yeast ribosome. Protein EcL11 induced a 10% increase in
L12-defective cell growth rate, although the in vitro
polymerizing capacity of the EcL11-containing ribosomes is
restored in a higher proportion, and, moreover, the particles
became partially sensitive to the prokaryotic specific
antibiotic thiostrepton. Molecular dynamic simulations using
modelled complexes support the correct assembly of bacterial L11
into the yeast ribosome and confirm its direct implication of
its CTD in the binding of thiostrepton to ribosomes.
PMID: 17940088 |
