Characterization of Thymidine Kinase Encoded by Channel Catfish Virus

Abstract

The thymidine kinase (TK) encoded by channel catfish virus (CCV) was demonstrated to be biochemically distinguishable from the TK of the host cell line, channel catfish ovary (CCO), as well as from TKs encoded by other herpesviruses. Extracts of CCO cells and of TK-negative CCO cells infected with CCV were assayed for differences in inhibition by deoxynucleosides, in feedback inhibition mediated by thymidine triphosphate (dTTP), and in phosphate donor specificity. Results indicated that, compared with CCO-encoded TK, CCV-encoded TK was more inhibited by deoxypurines and showed less dTTP-mediated feedback inhibition. The CCV-TK was unique among herpesvirus TKs in its inability to utilize CTP as a phosphate donor.