S. cerevisiae ribosome biogenesis is a highly ordered and dynamic process that involves over 100 accessory proteins, including 18 DExD/H-box proteins that act at discrete steps in the pathway. Although often termed RNA helicases, the biochemical functions of individual DExD/H-box proteins appear to vary considerably. Four DExD/H-box proteins, Dbp3p, Dbp4p, Rok1p, and Rrp3p, involved in yeast ribosome assembly were expressed in E. coli, and all were found to be active RNA-dependent ATPases with k cat values ranging from 13 to 170 min (-1) and K M(ATP) values ranging from 0.24 to 2.3 mM. All four proteins are activated by single-stranded oligonucleotides, but they require different chain lengths for maximal ATPase activity, ranging from 10 to >40 residues. None of the four proteins shows significant specificity for yeast rRNA, compared to nonspecific control RNAs since these large RNAs contain multiple binding sites that appear to be catalytically similar. This systematic comparison of four members of the DExD/H-box family demonstrates a range of biochemical properties and lays the foundation for relating the activities of proteins to their biological functions.
|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|