The thymidine kinase gene of herpes simplex virus type 1: cell-free protein synthesis and substrate specificity studies.

The HSV thymidine kinase genetic system has a number of advantages for the study of virus and cell genetics. Both forward and reverse mutants are readily selected. The enzyme can be assayed directly in the presence of the cell TK by the choice of the appropriate substrate, for example, 125IdC. The gene product, HSV TK, can be identified by SDS-polyacrylamide gel electrophoresis and mutants can be found with alterations in the electrophoretogram. The in vitro synthesis of HSV TK in response to HSV mRNA has been achieved and can be used to analyse specific mutant virus.