title: Cross-linking of L5 protein to 5 S RNA in rat liver 60-S subunits by ultraviolet irradiation.
abstract: After rat liver 60-S ribosomal subunits were irradiated with ultraviolet light at 254 nm, they were treated with EDTA and then subjected to sucrose density-gradient centrifugation to isolate 5 S RNA-protein complex. When 5 S RNA-protein was analyzed by SDS-acrylamide gel electrophoresis which dissociated noncovalent 5 S RNA-protein, two protein bands were observed. The one showed a slower mobility than the protein band (L5) of 5 S RNA-protein from non-irradiated 60 S subunit and the other showed the same mobility as L5 protein. Since the former band was shown to be specific to ultraviolet-irradiation, it was considered as cross-linked 5 S RNA-protein. After the two protein bands were iodinated with 125 I, labeled protein was extracted and treated with RNAase. Thereafter, it was analyzed by two-dimensional acrylamide gel electrophoresis, followed by autoradiography. The results indicate that the protein component of cross-linked 5 S RNA-protein is L5 protein (ribosomal protein; these proteins are designated according to the proposed uniform nomenclature. The correlation between that and our nomenclature was reported by McConkey et al. (1979) Mol. Gen. Genet. 169, 1-6. They also confirm the results previously reported (Terao, K., Takahashi, Y. and O(gata, K. (1975) Biochim. Biophys. Acta 402, 230-237).
mesh_terms: D000818:Animals; D004591:Electrophoresis, Polyacrylamide Gel; D008099:Liver / Q000648:ultrastructure; D012335:RNA, Ribosomal / Q000528:radiation effects*; D051381:Rats; D012269:Ribosomal Proteins / Q000528:radiation effects*; D014466:Ultraviolet Rays
chemical_list: D012335:RNA, Ribosomal; D012269:Ribosomal Proteins