Abstract
Ribosomes are essential macromolecular complexes conducting protein biosynthesis in all domains of life. Cells can have heterogeneous ribosomes, i.e. ribosomes with various ribosomal RNA and ribosomal protein (r-protein) composition. However, the functional importance of heterogeneous ribosomes has remained elusive. One of the possible sources for ribosome heterogeneity is provided by paralogous r-proteins. In E. coli, ribosomal protein bL31 has two paralogs: bL31A encoded by rpmE and bL31B encoded by ykgM. This study investigates phenotypic effects of these ribosomal protein paralogs using bacterial strains expressing only bL31A or bL31B. We show that bL31A confers higher fitness to E. coli under lower temperatures. In addition, bL31A and bL31B have different effects on translation reading frame maintenance and apparent translation processivity in vivo as demonstrated by dual luciferase assay. In general, this study demonstrates that ribosomal protein paralog composition (bL31A versus bL31B) can affect cell growth and translation outcome.
Highlights
To survive, grow and reproduce organisms need proteins that function as enzymes, messengers, structural components of intra- and intercellular structures, transport and storage molecules
An emerging paradigm is ribosome composition mediated translational c ontrol[3] that is based on the hypothesis that ribosome can regulate translation via its composition. This concept is based on the accumulating evidence that eukaryotic and bacterial cells produce heterogeneous ribosomes, i.e. ribosomes containing alternative components[4,5]
As translation initiation is the main regulatory checkpoint for protein synthesis most research on the functionality of ribosome heterogeneity has been focused on this step of translation[6]
Summary
Grow and reproduce organisms need proteins that function as enzymes, messengers, structural components of intra- and intercellular structures, transport and storage molecules. An emerging paradigm is ribosome composition mediated translational c ontrol[3] that is based on the hypothesis that ribosome can regulate translation via its composition This concept is based on the accumulating evidence that eukaryotic and bacterial cells produce heterogeneous ribosomes, i.e. ribosomes containing alternative components[4,5]. In addition to rRNA sequence variations, bacterial ribosomes can contain differently modified r RNA14 and ribosomal p roteins[15] and substoichiometric amounts of r-proteins[16,17] but their functional importance has remained elusive. Another possibility to create heterogeneous ribosomes is to produce ribosomes differing in their r-protein paralog content. Paralogs of the latter group have fairly different amino acid sequences (identity < 50%)[18]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
