DNA Cleavage and Packaging Proteins Encoded by Genes U L 28, U L 15, and U L 33 of Herpes Simplex Virus Type 1 Form a Complex in Infected Cells

Abstract

ABSTRACT Previous studies have indicated that the U L 6, U L 15, U L 17, U L 28, U L 32, and U L 33 genes are required for the cleavage and packaging of herpes simplex viral DNA. To identify proteins that interact with the U L 28-encoded DNA binding protein of herpes simplex virus type 1 (HSV-1), a previously undescribed rabbit polyclonal antibody directed against the U L 28 protein fused to glutathione S -transferase was used to immunopurify U L 28 and the proteins with which it associated. It was found that the antibody specifically coimmunoprecipitated proteins encoded by the genes U L 28, U L 15, and U L 33 from lysates of both HEp-2 cells infected with HSV-1(F) and insect cells infected with recombinant baculoviruses expressing these three proteins. In reciprocal reactions, antibodies directed against the U L 15- or U L 33-encoded proteins also coimmunoprecipitated the U L 28 protein. The coimmunoprecipitation of the three proteins from HSV-infected cells confirms earlier reports of an association between the U L 28 and U L 15 proteins and represents the first evidence of the involvement of the U L 33 protein in this complex.