Involvement of mitochondrial ribosomal proteins in ribosomal RNA-mediated protein folding.
The peptidyl transferase center of the domain V of large ribosomal RNA in the prokaryotic and eukaryotic cytosolic ribosomes acts as general protein folding modulator. We showed earlier that one part of the domain V (RNA1 containing the peptidyl transferase loop) binds unfolded protein and directs it to a folding competent state (FCS) that is released by the other part (RNA2) to attain the folded native state by itself. Here we show that the peptidyl transferase loop of the mitochondrial ribosome releases unfolded proteins in FCS extremely slowly despite its lack of the rRNA segment analogous to RNA2. The release of FCS can be hastened by the equivalent activity of RNA2 or the large subunit proteins of the mitochondrial ribosome. The RNA2 or large subunit proteins probably introduce some allosteric change in the peptidyl transferase loop to enable it to release proteins in FCS.
Department of Biophysics, Molecular Biology and Bioinformatics, University College of Science, University of Calcutta, Kolkata 700009, India; Department of Biological Sciences, Indian Institute of Science Education and Research, Mohanpur, Nadia 741252, India.
Anindita
A
Das
Department of Biophysics, Molecular Biology and Bioinformatics, University College of Science, University of Calcutta, Kolkata 700009, India; Department of Microbiology, St. Xavier's College, Kolkata 700016, India.
Jaydip
J
Ghosh
Department of Biophysics, Molecular Biology and Bioinformatics, University College of Science, University of Calcutta, Kolkata 700009, India.
Arpita
A
Bhattacharya
Department of Biophysics, Molecular Biology and Bioinformatics, University College of Science, University of Calcutta, Kolkata 700009, India.
Dibyendu
D
Samanta
Department of Biophysics, Molecular Biology and Bioinformatics, University College of Science, University of Calcutta, Kolkata 700009, India.
Debasis
D
Das
Department of Biophysics, Molecular Biology and Bioinformatics, University College of Science, University of Calcutta, Kolkata 700009, India; Department of Biological Sciences, Indian Institute of Science Education and Research, Mohanpur, Nadia 741252, India. Electronic address: chanchaldg2000@yahoo.com.
Chanchal
C
Das Gupta
D000495:Allosteric Site; D000595:Amino Acid Sequence; D000818:Animals; D002417:Cattle; D004272:DNA, Mitochondrial / Q000378:metabolism; D004926:Escherichia coli / Q000378:metabolism; D006801:Humans; D007891:Leishmania / Q000378:metabolism; D008928:Mitochondria / Q000378:metabolism*; D008930:Mitochondria, Liver / Q000378:metabolism; D008969:Molecular Sequence Data; D009154:Mutation; D009690:Nucleic Acid Conformation; D017510:Protein Folding; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D012313:RNA / Q000737:chemistry; D012335:RNA, Ribosomal / Q000235:genetics* / Q000378:metabolism; D012270:Ribosomes / Q000737:chemistry / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid
D004272:DNA, Mitochondrial; D012335:RNA, Ribosomal; D012313:RNA