Abstract
In the assembly of a prespliceosome, U2 small nuclear ribonucleoprotein (snRNP) functions in pre-messenger RNA (mRNA) splicing together with splicing factors (SFs) 3a, SF3b, and several other proteins. The 17S but not the 12S form of U2 snRNP is active in splicing-complex formation. Here it is shown that the SF3a subunits correspond to three of the 17S U2 snRNP-specific polypeptides. SF3a interacts with U2 snRNP in the presence of SF3b to generate a structure similar to 17S U2 snRNP, which suggests a function for SF3a and SF3b in the incorporation of U2 snRNP into the spliceosome. Furthermore, the 60-kilodalton subunit of SF3a is related to the yeast splicing protein PRP9.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Adenosine Triphosphate / metabolism
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Cross Reactions
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Electrophoresis, Polyacrylamide Gel
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Fungal Proteins / chemistry
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Fungal Proteins / immunology
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Fungal Proteins / metabolism*
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Humans
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Nuclear Proteins / chemistry
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Nuclear Proteins / immunology
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Nuclear Proteins / metabolism*
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RNA Splicing Factors
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RNA Splicing*
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RNA-Binding Proteins
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Ribonucleoprotein, U2 Small Nuclear / chemistry
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Ribonucleoprotein, U2 Small Nuclear / metabolism*
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Saccharomyces cerevisiae Proteins*
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Spliceosomes / metabolism*
Substances
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Fungal Proteins
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Nuclear Proteins
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PRP9 protein, S cerevisiae
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RNA Splicing Factors
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RNA-Binding Proteins
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Ribonucleoprotein, U2 Small Nuclear
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Saccharomyces cerevisiae Proteins
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Adenosine Triphosphate