A protein factor that specifically binds to the 5'-untranslated region of encephalomyocarditis virus (EMCV) RNA has been found in extracts of ascites carcinoma Krebs-2 cells. This was done using UV-irradiation on extracts supplemented with in vitro synthesized 32P-labelled transcripts followed by analysis of crosslinked proteins by SDS-polyacrylamide gel electrophoresis. The transcripts represented the viral RNA sequence from nt 315 to 1155, its derivatives with internal deletions or truncated forms. This set of transcripts has allowed us to find out that the factor (p58) binds to EMCV RNA within the sequence 315–485.
