English: E. coli (BL21) cells were transformed with plasmids expressing GST-HCMV ORF (ampicillin-resistant) or cotransformed with plasmids expressing GST-HCMV ORF and pT-E1E2S1 (chloramphenicol-resistant). One milliliter of bacterial cell culture was induced with 0.4 mM IPTG for 5 h at 30°C. Total cell lysates were prepared by boiling the cell pellet in 200 µl of 1× protein loading dye. Clarified cell lysates were separated by SDS-PAGE, and immunoblot analysis was performed with anti-GST antibody. HCMV ORFs fused to GST and the ORF sizes (number of amino acids in parenthesis) are indicated. The SUMO-modified forms of UL123 (IE1), UL122 (IE2), and US34A are indicated as open arrowheads.