English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

The PRP4 protein of Saccharomyces cerevisiae is an essential part of the U4/U6 snRNP, a component of the mRNA splicing apparatus. As an approach to the determination of structure-function relationships in the PRP4 protein, we have isolated more than fifty new alleles of the PRP4 gene through random and site-directed mutagenesis, and have analyzed the phenotypes of many of them. Twelve of the fourteen single-point mutations that give rise to temperature-sensitive (ts) or null phenotypes are located in the portion of the PRP4 gene that corresponds to the beta-transducin-like region of the protein; the remaining two are located in the central portion of the gene, one of them in an arginine-lysine-rich region. Nine additional deletion or deletion/insertion mutations were isolated at both the amino- and carboxy-termini. These data show that the amino-terminal region (108 amino acids) of PRP4 is non-essential, while the carboxy-terminal region is essential up to the penultimate amino acid. A deletion of one entire beta-transducin-like repeat (the third of five) resulted in a null phenotype. All ts mutants show a first-step defect in the splicing of U3 snRNA primary transcript in vivo at the non-permissive temperature. The effects on prp4 mutant growth of increased copy-number of mutant prp4 genes themselves, and of genes for other components of the U4/U6 snRNP (PRP3 and U6 snRNA) have also been studied. We suggest that the PRP4 protein has at least three domains: a non-essential amino-terminal segment of at least 108 amino acids, a central basic region of about 140 residues that is relatively refractile to mutation and might be involved in RNA interaction, and an essential carboxy-terminal region of about 210 residues with the five repeat-regions that are similar to beta-transducins, which might be involved in protein-protein interaction. A model of interactions of snRNP components suggested by these results is presented.

Mutational analysis of the PRP4 protein ofSaccharomyces cerevisiaesuggests domain structure and snRNP interactions