title: A Possible Role of the Full-Length Nascent Protein in Post-Translational Ribosome Recycling.
abstract: Each cycle of translation initiation in bacterial cell requires free 50S and 30S ribosomal subunits originating from the post-translational dissociation of 70S ribosome from the previous cycle. Literature shows stable dissociation of 70S from model post-termination complexes by the concerted action of Ribosome Recycling Factor (RRF) and Elongation Factor G (EF-G) that interact with the rRNA bridge B2a/B2b joining 50S to 30S. In such experimental models, the role of full-length nascent protein was never considered seriously. We observed relatively slow release of full-length nascent protein from 50Sof post translation ribosome, and in that process, its toe prints on the rRNA in vivo and in in vitro translation with E.coli S30 extract. We reported earlier that a number of chemically unfolded proteins like bovine carbonic anhydrase (BCA), lactate dehydrogenase (LDH), malate dehydrogenase (MDH), lysozyme, ovalbumin etc., when added to free 70Sin lieu of the full length nascent proteins, also interact with identical RNA regions of the 23S rRNA. Interestingly the rRNA nucleotides that slow down release of the C-terminus of full-length unfolded protein were found in close proximity to the B2a/B2b bridge. It indicated a potentially important chemical reaction conserved throughout the evolution. Here we set out to probe that conserved role of unfolded protein conformation in splitting the free or post-termination 70S. How both the RRF-EFG dependent and the plausible nascent protein-EFG dependent ribosome recycling pathways might be relevant in bacteria is discussed here.
authors.affiliation: Department of Biophysics, Molecular Biology and Bioinformatics, University College of Science, University of Calcutta, Kolkata, India.
authors.forename: Debasis
authors.initials: D
authors.lastname: Das
authors.affiliation: Department of Biophysics, Molecular Biology and Bioinformatics, University College of Science, University of Calcutta, Kolkata, India.
authors.forename: Dibyendu
authors.initials: D
authors.lastname: Samanta
authors.affiliation: Department of Biophysics, Molecular Biology and Bioinformatics, University College of Science, University of Calcutta, Kolkata, India.
authors.forename: Arpita
authors.initials: A
authors.lastname: Bhattacharya
authors.affiliation: Department of Biophysics, Molecular Biology and Bioinformatics, University College of Science, University of Calcutta, Kolkata, India.|Department of Microbiology, Raidighi College, Raidighi, 24 Parganas (S), West Bengal, India.
authors.forename: Arunima
authors.initials: A
authors.lastname: Basu
authors.affiliation: Department of Biophysics, Molecular Biology and Bioinformatics, University College of Science, University of Calcutta, Kolkata, India.
authors.forename: Anindita
authors.initials: A
authors.lastname: Das
authors.affiliation: Department of Microbiology, St. Xavier's College, Kolkata, India.
authors.forename: Jaydip
authors.initials: J
authors.lastname: Ghosh
authors.affiliation: Crystallography & Molecular Biology Division, Saha Institute of Nuclear Physics, HBNI, Kolkata, India.
authors.forename: Abhijit
authors.initials: A
authors.lastname: Chakrabarti
authors.affiliation: Department of Biophysics, Molecular Biology and Bioinformatics, University College of Science, University of Calcutta, Kolkata, India.|Department of Life Sciences and Biotechnology, Jadavpur University, Kolkata, India.
authors.forename: Chanchal
authors.initials: C
authors.lastname: Das Gupta
mesh_terms: D000818:Animals; D002256:Carbonic Anhydrases / Q000378:metabolism; D002417:Cattle; D002642:Chick Embryo; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D008291:Malate Dehydrogenase / Q000378:metabolism; D009113:Muramidase / Q000378:metabolism; D010047:Ovalbumin / Q000378:metabolism; D010442:Peptide Chain Initiation, Translational / Q000502:physiology*; D010443:Peptide Chain Termination, Translational / Q000502:physiology*; D020653:Peptide Elongation Factor G / Q000378:metabolism; D014176:Protein Biosynthesis / Q000502:physiology*; D017510:Protein Folding; D012269:Ribosomal Proteins / Q000378:metabolism; D054681:Ribosome Subunits, Large, Bacterial / Q000378:metabolism*; D054680:Ribosome Subunits, Small, Bacterial / Q000378:metabolism*; D013552:Swine
chemical_list: D020653:Peptide Elongation Factor G; D012269:Ribosomal Proteins; C087267:ribosome releasing factor; D010047:Ovalbumin; D007770:L-Lactate Dehydrogenase; D008291:Malate Dehydrogenase; D009113:Muramidase; D002256:Carbonic Anhydrases