Figure 1.

Comparative analysis of proteins that UV crosslink to Eg1, Eg2, Eg5 and c-mos 3'UTRs.³²P-labeled transcripts corresponding to the 3' untranslated regions of the RNAs indicated above the lanes were incubated in extracts made from 4 hour (pre-transcription) Xenopus embryos, irradiated with UV light and digested with RNase A. The proteins rendered radioactive by crosslinking to the labeled transcripts were analysed by electrophoresis on 10% polyacrylamide-SDS gels followed by autoradiography. A³²P-UTP labeled RNAs; B³²P-ATP labeled RNAs; C³²P-GTP labeled RNAs; D³²P-CTP labeled RNAs. In each panel the sizes of the molecular weight markers are indicated on the left.