The structure of the U-box in the essential Saccharomyces cerevisiae pre-mRNA splicing factor Prp19p has been determined by NMR. The conserved zinc-binding sites supporting the cross-brace arrangement in RING-finger domains are replaced by hydrogen-bonding networks in the U-box. These hydrogen-bonding networks are necessary for the structural stabilization and activity of the U-box. A conservative Val-->Ile point mutation in the Prp19p U-box domain leads to pre-mRNA splicing defects in vivo. NMR analysis of this mutant shows that the substitution disrupts structural integrity of the U-box domain. Furthermore, comparison of the Prp19p U-box domain with known RING-E2 complex structures demonstrates that both U-box and RING-fingers contain a conserved interaction surface. Mutagenesis of residues at this interface, while not perturbing the structure of the U-box, abrogates Prp19p function in vivo. These comparative structural and functional analyses imply that the U-box and its associated ubiquitin ligase activity are critical for Prp19p function in vivo.
|Evidence ID||Analyze ID||Interactor||Interactor Systematic Name||Interactor||Interactor Systematic Name||Type||Assay||Annotation||Action||Modification||Phenotype||Source||Reference||Note|
|Evidence ID||Analyze ID||Gene||Gene Systematic Name||Gene Ontology Term||Gene Ontology Term ID||Qualifier||Aspect||Method||Evidence||Source||Assigned On||Reference||Annotation Extension|
|Evidence ID||Analyze ID||Gene||Gene Systematic Name||Phenotype||Experiment Type||Experiment Type Category||Mutant Information||Strain Background||Chemical||Details||Reference|
|Evidence ID||Analyze ID||Regulator||Regulator Systematic Name||Target||Target Systematic Name||Experiment||Conditions||Strain||Source||Reference|