Cargando…

Ribosome binding sites visualized on freeze-fractured membranes of the rough endoplasmic reticulum

Freeze-fracture micrographs of cells of the green alga Micrasterias denticulata stabilized by ultrarapid freezing reveal imprints of polysomes on the rough endoplasmic reticulum membranes. The imprints appear as broad, spiral ridges on the P faces and as corresponding wide grooves on the E faces of...

Descripción completa

Detalles Bibliográficos
Formato: Texto
Lenguaje:English
Publicado: The Rockefeller University Press 1980
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2110593/
https://www.ncbi.nlm.nih.gov/pubmed/7364870
_version_ 1782139617278951424
collection PubMed
description Freeze-fracture micrographs of cells of the green alga Micrasterias denticulata stabilized by ultrarapid freezing reveal imprints of polysomes on the rough endoplasmic reticulum membranes. The imprints appear as broad, spiral ridges on the P faces and as corresponding wide grooves on the E faces of the membranes. Distinct 110-A particles with a spacing of 270 +/- 45 A are associated with the P-face ridges. Where imprints of individual ribosomes can be discerned, it is seen that there is a 1:1 relationship between the ribosomes and the 110-A particles, and that the 110-A particles are located in a peripheral position with respect to the polysome spirals. We propose that the 110- A particles could be structural equivalents of ribosome-binding sites, consisting of a molecule each of ribophorins I and II and a nascent polypeptide chain. These observations suggest that the spiral form of polysomes could result from the forces generated by the extrusion of the growing polypeptide chains to one side of the polysome.
format Text
id pubmed-2110593
institution National Center for Biotechnology Information
language English
publishDate 1980
publisher The Rockefeller University Press
record_format MEDLINE/PubMed
spelling pubmed-21105932008-05-01 Ribosome binding sites visualized on freeze-fractured membranes of the rough endoplasmic reticulum J Cell Biol Articles Freeze-fracture micrographs of cells of the green alga Micrasterias denticulata stabilized by ultrarapid freezing reveal imprints of polysomes on the rough endoplasmic reticulum membranes. The imprints appear as broad, spiral ridges on the P faces and as corresponding wide grooves on the E faces of the membranes. Distinct 110-A particles with a spacing of 270 +/- 45 A are associated with the P-face ridges. Where imprints of individual ribosomes can be discerned, it is seen that there is a 1:1 relationship between the ribosomes and the 110-A particles, and that the 110-A particles are located in a peripheral position with respect to the polysome spirals. We propose that the 110- A particles could be structural equivalents of ribosome-binding sites, consisting of a molecule each of ribophorins I and II and a nascent polypeptide chain. These observations suggest that the spiral form of polysomes could result from the forces generated by the extrusion of the growing polypeptide chains to one side of the polysome. The Rockefeller University Press 1980-04-01 /pmc/articles/PMC2110593/ /pubmed/7364870 Text en This article is distributed under the terms of an Attribution–Noncommercial–Share Alike–No Mirror Sites license for the first six months after the publication date (see http://www.rupress.org/terms). After six months it is available under a Creative Commons License (Attribution–Noncommercial–Share Alike 4.0 Unported license, as described at http://creativecommons.org/licenses/by-nc-sa/4.0/).
spellingShingle Articles
Ribosome binding sites visualized on freeze-fractured membranes of the rough endoplasmic reticulum
title Ribosome binding sites visualized on freeze-fractured membranes of the rough endoplasmic reticulum
title_full Ribosome binding sites visualized on freeze-fractured membranes of the rough endoplasmic reticulum
title_fullStr Ribosome binding sites visualized on freeze-fractured membranes of the rough endoplasmic reticulum
title_full_unstemmed Ribosome binding sites visualized on freeze-fractured membranes of the rough endoplasmic reticulum
title_short Ribosome binding sites visualized on freeze-fractured membranes of the rough endoplasmic reticulum
title_sort ribosome binding sites visualized on freeze-fractured membranes of the rough endoplasmic reticulum
topic Articles
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2110593/
https://www.ncbi.nlm.nih.gov/pubmed/7364870