In vitro protein folding by ribosomes from Escherichia coli, wheat germ and rat liver: the role of the 50S particle and its 23S rRNA.
Ribosomes from a number of prokaryotic and eukaryotic sources (e.g. Escherichia coli, wheat germ and rat liver) can refold a number of enzymes which are denatured with guanidine/HC1 prior to incubation with ribosomes. In this report, we present our observations on the refolding of denatured lactate dehydrogenase from rabbit muscle and glucose-6-phosphate dehydrogenase from baker's yeast by ribosomes from E. coli, wheat germ and rat liver. The protein-folding activity of E. coli ribosomes was found to be present in 50S particles and in 23S rRNA. The 30S particle or 16S rRNA did not show any protein-folding activity. The protein-folding activity of 23S rRNA may depend on its tertiary conformation. Loss of tertiary structure, by incubation with low concentrations of EDTA, inhibited the protein-folding activity of 23S rRNA. This low concentration of EDTA had no effect on folding of the denatured enzymes by themselves.
Das
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Department of Biophysics, Molecular Biology and Genetics, University of Calcutta, India.
Chattopadhyay
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Bera
A K
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Dasgupta
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D000818:Animals; D002384:Catalysis; D004926:Escherichia coli / Q000502:physiology* / Q000648:ultrastructure; D005260:Female; D005954:Glucosephosphate Dehydrogenase / Q000378:metabolism; D007700:Kinetics; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D008099:Liver / Q000502:physiology* / Q000648:ultrastructure; D008297:Male; D009690:Nucleic Acid Conformation; D011489:Protein Denaturation; D017510:Protein Folding; D012338:RNA, Ribosomal, 23S / Q000737:chemistry / Q000502:physiology*; D011817:Rabbits; D051381:Rats; D012270:Ribosomes / Q000502:physiology*; D014908:Triticum / Q000502:physiology* / Q000648:ultrastructure
D012338:RNA, Ribosomal, 23S; D007770:L-Lactate Dehydrogenase; D005954:Glucosephosphate Dehydrogenase