Ribosome Mediated Quinary Interactions Modulate In-Cell Protein Activities.
Biochemistry
; 56(32): 4117-4126, 2017 08 15.
Article
em En
| MEDLINE
| ID: mdl-28715177
ABSTRACT
Ribosomes are present inside bacterial cells at micromolar concentrations and occupy up to 20% of the cell volume. Under these conditions, even weak quinary interactions between ribosomes and cytosolic proteins can affect protein activity. By using in-cell and in vitro NMR spectroscopy, and biophysical techniques, we show that the enzymes, adenylate kinase and dihydrofolate reductase, and the respective coenzymes, ATP and NADPH, bind to ribosomes with micromolar affinity, and that this interaction suppresses the enzymatic activities of both enzymes. Conversely, thymidylate synthase, which works together with dihydrofolate reductase in the thymidylate synthetic pathway, is activated by ribosomes. We also show that ribosomes impede diffusion of green fluorescent protein in vitro and contribute to the decrease in diffusion in vivo. These results strongly suggest that ribosome-mediated quinary interactions contribute to the differences between in vitro and in vivo protein activities and that ribosomes play a previously under-appreciated nontranslational role in regulating cellular biochemistry.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Ribossomos
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Tetra-Hidrofolato Desidrogenase
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Adenilato Quinase
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Ressonância Magnética Nuclear Biomolecular
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Proteínas de Escherichia coli
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Escherichia coli
Idioma:
En
Revista:
Biochemistry
Ano de publicação:
2017
Tipo de documento:
Article
País de afiliação:
Estados Unidos