Rat RL23a ribosomal protein efficiently competes with its Saccharomyces cerevisiae L25 homologue for assembly into 60 S subunits

摘要: The large subunit protein RL23a from rat liver ribosomes shows 62% sequence identity with the primary rRNA-binding ribosomal L25 Saccharomyces cerevisiae. In vitro binding studies indicated that both r-proteins are able to recognise site on yeast 25 S rRNA and its structural homologue mammalian 28 equal efficiency. To determine whether two also functionally equivalent in vivo, a single plasmid-borne copy of either wild-type gene or cDNA, driven by promoter, was introduced into strain which chromosomal is under control glucose-repressible GALI-10 promoter. No difference growth rate could be detected between types transformants when cultured glucose-based medium. cells co-express epitope-tagged versions single-copy genes, approximately 35% 60 subunits contained heterologous as determined Western analysis. This value increased 55% overexpressing using multi-copy plasmid. These data demonstrate can act highly efficient substitute for counterpart assembly functional even presence endogenous protein.