title: Ribosomal proteins cross-linked to 28-S and 18-S rRNA separated by sedimentation after ultraviolet irradiation of rat-liver ribosomes.
abstract: Rat liver 80-S ribosomes, irradiated with 254 nm ultraviolet light for 15-60 min (0.63-2.5 X 10(5) quanta/ribosome), were treated with sodium dodecyl sulfate; 18-S and 28-S RNA fractions were isolated by sucrose density-gradient centrifugation. The protein moieties of the 18-S and 28-S rRNA fractions were labeled with 125I. After digestion of the rRNA fractions with RNase A and T1, the cross-linked proteins were analyzed by two-dimensional acrylamide gel electrophoresis and then autoradiography. Cross-linked proteins were examined further by dodecyl sulfate/acrylamide gel electrophoresis of individual radioactive spots of proteins and their proteolytic peptides on two-dimensional gels. The results showed that S2 and S15 were cross-linked to 18-S rRNA, and L5, L6 and L8 to 28-S rRNA. Similar results were obtained when isolated 40-S or 60-S subunits were irradiated.
mesh_terms: D000818:Animals; D002499:Centrifugation, Density Gradient; D066298:In Vitro Techniques; D008099:Liver / Q000378:metabolism / Q000528:radiation effects*; D011485:Protein Binding; D012335:RNA, Ribosomal / Q000302:isolation & purification / Q000378:metabolism*; D051381:Rats; D012269:Ribosomal Proteins / Q000302:isolation & purification / Q000378:metabolism*; D012270:Ribosomes / Q000378:metabolism / Q000528:radiation effects*; D014466:Ultraviolet Rays
chemical_list: D012335:RNA, Ribosomal; D012269:Ribosomal Proteins