| Literature DB >> 2147057 |
Abstract
U4 snRNA is phylogenetically highly conserved and organized in several domains. To determine the function of each of the domains of human U4 snRNA in the multi-step process of snRNP and spliceosome assembly, we used reconstitution procedures in combination with snRNA mutagenesis. The highly conserved 5' terminal domain of U4 snRNA consists of the stem I and stem II regions that have been proposed to base pair with U6 snRNA, and the 5' stem-loop structure. We found that each of these structural elements is essential for spliceosome assembly. However, only the stem II region is required for U4-U6 interaction, and none of these elements for Sm protein binding. In contrast, the 3' terminal domain of U4 snRNA containing the Sm binding site is dispensable for both U4-U6 interaction and spliceosome assembly. Our results support an organization of the U4 snRNP into multiple functional domains, each of which acts at distinct stages of snRNP and spliceosome assembly.Entities:
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Year: 1990 PMID: 2147057 PMCID: PMC332485 DOI: 10.1093/nar/18.21.6223
Source DB: PubMed Journal: Nucleic Acids Res ISSN: 0305-1048 Impact factor: 16.971