Immunoprecipitation of proteins encoded by full-length (49.5) and N-terminally truncated UL49.5 (49.5T) synthesized in vitro with antibodies (Ab) directed against fusion proteins containing the full-length UL49.5 protein (lanes 2 and 7), the truncated protein (lanes 3 and 8), GST (lanes 4 and 9), or gM (lane 5). For comparison, 1 μl of the unprecipitated UL49.5 translation reaction (lane 1) and 5 μl of the UL49.5T translation reaction (lane 6) were loaded. Each immunoprecipitation was begun with 5 μl of translation reaction mixture. Samples were analyzed by SDS-PAGE in an 18% gel and autoradiographed. Ag, antigen.