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Combined Biochemical and Electron Microscopic Analyses Reveal the Architecture of the Mammalian U2 snRNP
The 17S U2 small nuclear ribonucleoprotein particle (snRNP) represents the active form of U2 snRNP that binds to the pre-mRNA during spliceosome assembly. This particle forms by sequential interactions of splicing factors SF3b and SF3a with the 12S U2 snRNP. We have purified SF3b and the 15S U2 snRN...
Autores principales: | , , , |
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Formato: | Texto |
Lenguaje: | English |
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The Rockefeller University Press
1999
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2133165/ https://www.ncbi.nlm.nih.gov/pubmed/10385517 |
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author | Krämer, Angela Grüter, Patric Gröning, Karsten Kastner, Berthold |
author_facet | Krämer, Angela Grüter, Patric Gröning, Karsten Kastner, Berthold |
author_sort | Krämer, Angela |
collection | PubMed |
description | The 17S U2 small nuclear ribonucleoprotein particle (snRNP) represents the active form of U2 snRNP that binds to the pre-mRNA during spliceosome assembly. This particle forms by sequential interactions of splicing factors SF3b and SF3a with the 12S U2 snRNP. We have purified SF3b and the 15S U2 snRNP, an intermediate in the assembly pathway, from HeLa cell nuclear extracts and show that SF3b consists of four subunits of 49, 130, 145, and 155 kD. Biochemical analysis indicates that both SF3b and the 12S U2 snRNP are required for the incorporation of SF3a into the 17S U2 snRNP. Nuclease protection studies demonstrate interactions of SF3b with the 5′ half of U2 small nuclear RNA, whereas SF3a associates with the 3′ portion of the U2 snRNP and possibly also interacts with SF3b. Electron microscopy of the 15S U2 snRNP shows that it consists of two domains in which the characteristic features of isolated SF3b and the 12S U2 snRNP are conserved. Comparison to the two-domain structure of the 17S U2 snRNP corroborates the biochemical results in that binding of SF3a contributes to an increase in size of the 12S U2 domain and possibly induces a structural change in the SF3b domain. |
format | Text |
id | pubmed-2133165 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 1999 |
publisher | The Rockefeller University Press |
record_format | MEDLINE/PubMed |
spelling | pubmed-21331652008-05-01 Combined Biochemical and Electron Microscopic Analyses Reveal the Architecture of the Mammalian U2 snRNP Krämer, Angela Grüter, Patric Gröning, Karsten Kastner, Berthold J Cell Biol Regular Articles The 17S U2 small nuclear ribonucleoprotein particle (snRNP) represents the active form of U2 snRNP that binds to the pre-mRNA during spliceosome assembly. This particle forms by sequential interactions of splicing factors SF3b and SF3a with the 12S U2 snRNP. We have purified SF3b and the 15S U2 snRNP, an intermediate in the assembly pathway, from HeLa cell nuclear extracts and show that SF3b consists of four subunits of 49, 130, 145, and 155 kD. Biochemical analysis indicates that both SF3b and the 12S U2 snRNP are required for the incorporation of SF3a into the 17S U2 snRNP. Nuclease protection studies demonstrate interactions of SF3b with the 5′ half of U2 small nuclear RNA, whereas SF3a associates with the 3′ portion of the U2 snRNP and possibly also interacts with SF3b. Electron microscopy of the 15S U2 snRNP shows that it consists of two domains in which the characteristic features of isolated SF3b and the 12S U2 snRNP are conserved. Comparison to the two-domain structure of the 17S U2 snRNP corroborates the biochemical results in that binding of SF3a contributes to an increase in size of the 12S U2 domain and possibly induces a structural change in the SF3b domain. The Rockefeller University Press 1999-06-28 /pmc/articles/PMC2133165/ /pubmed/10385517 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 | Regular Articles Krämer, Angela Grüter, Patric Gröning, Karsten Kastner, Berthold Combined Biochemical and Electron Microscopic Analyses Reveal the Architecture of the Mammalian U2 snRNP |
title | Combined Biochemical and Electron Microscopic Analyses Reveal the Architecture of the Mammalian U2 snRNP |
title_full | Combined Biochemical and Electron Microscopic Analyses Reveal the Architecture of the Mammalian U2 snRNP |
title_fullStr | Combined Biochemical and Electron Microscopic Analyses Reveal the Architecture of the Mammalian U2 snRNP |
title_full_unstemmed | Combined Biochemical and Electron Microscopic Analyses Reveal the Architecture of the Mammalian U2 snRNP |
title_short | Combined Biochemical and Electron Microscopic Analyses Reveal the Architecture of the Mammalian U2 snRNP |
title_sort | combined biochemical and electron microscopic analyses reveal the architecture of the mammalian u2 snrnp |
topic | Regular Articles |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2133165/ https://www.ncbi.nlm.nih.gov/pubmed/10385517 |
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