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. 1971 Oct;68(10):2453–2457. doi: 10.1073/pnas.68.10.2453

Rapid Exchange of Subunits between Free Ribosomes in Extracts of Escherichia coli

Alap R Subramanian 1, Bernard D Davis 1
PMCID: PMC389442  PMID: 4944627

Abstract

The runoff of a mixture of “heavy” and “light” polysomes has been reported to yield hybrid ribosomes, of intermediate density. However, we found that the dissociation of free heavy ribosomes as they advance in a sucrose gradient causes a serious artefact in the demonstration of hybrid ribosomes. This artefact is eliminated by fixation with glutaraldehyde before sedimentation. Formation of hybrid ribosomes can then be demonstrated, but it is equally complete whether the heavy and light preparations are mixed before or after runoff. Hence, free ribosomes exchange subunits rapidly in extracts. The previously reported exchange thus does not provide evidence for formation of free subunits during runoff.

Keywords: density gradient centrifugation, glutaraldehyde fixation, run-off ribosomes, polyribosomes

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

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