FIG 3.

TISU forms specific contacts with ribosomal proteins. (Top) Schematic representation of the fragments used for in vitro transcription and UV cross-linking. (Bottom) Comparison of the cross-linking profile of +5 and +6 positions of the canonical and TISU AUG codons. These mRNAs were modified with a thio-U at +5 and +6 positions and were incubated with rabbit reticulocyte lysate in the presence of GMP-PNP (48S) or cycloheximide (80S) and then were subjected to 365-nm UV irradiation followed by RNase treatment. The cross-linked proteins were analyzed by 15% SDS-PAGE and autoradiography. Red arrows denote specific cross-linked polypeptides. The numbers on the right denote molecular masses in kilodaltons.