Photo‐induced protein cross‐linking to 5S RNA and 28–5.8S RNA within rat‐liver 60S ribosomal subunits

Abstract

Rat liver 60S ribosomal subunits were irradiated with 254-nm ultraviolet light (1.26 .times. 104 quanta/subunit), under conditions which perserved their functional activity. Cross-linked RNA-protein complexes were recovered after unreacted proteins were removed by repeated acetic acid extractions. Proteins linked to the whole rRNA, to 5S RNA and to 28-5.8S RNA were identified by 2-dimensional gel electrophoresis after RNA hydrolysis by ribonucleases T1 and A. Apparently, numerous proteins interact with rRNA (at least 10 with 28-5.8S RNA, 8 with 5S RNA and among these 3 are common to both) and were discussed in the light of all the available data.