title: Characterization of the RNase R association with ribosomes.
abstract: BACKGROUND
  In this study we employed the TAP tag purification method coupled with mass spectrometry analysis to identify proteins that co-purify with Escherichia coli RNase R during exponential growth and after temperature downshift.
  
  
  RESULTS
  Our initial results suggested that RNase R can interact with bacterial ribosomes. We subsequently confirmed this result using sucrose gradient ribosome profiling joined with western blot analysis. We found that RNase R co-migrates with the single 30S ribosomal subunits. Independent data involving RNase R in the rRNA quality control process allowed us to hypothesize that the RNase R connection with ribosomes has an important physiological role.
  
  
  CONCLUSIONS
  This study leads us to conclude that RNase R can interact with ribosomal proteins and that this interaction may be a result of this enzyme involvement in the ribosome quality control.
authors: Michal
authors: M
authors: Malecki
authors: Cátia
authors: C
authors: Bárria
authors: Instituto de Tecnologia Química e Biológica (ITQB), Oeiras, Portugal. cecilia@itqb.unl.pt.
authors: Cecilia M
authors: CM
authors: Arraiano
mesh_terms: D015153:Blotting, Western; D002499:Centrifugation, Density Gradient; D004926:Escherichia coli / Q000201:enzymology* / Q000254:growth & development / Q000378:metabolism* / Q000528:radiation effects; D029968:Escherichia coli Proteins / Q000378:metabolism*; D005095:Exoribonucleases / Q000378:metabolism*; D011485:Protein Binding; D012270:Ribosomes / Q000378:metabolism*; D013696:Temperature
chemical_list: D029968:Escherichia coli Proteins; C489683:rnr protein, E coli; D005095:Exoribonucleases