Allosteric interaction of a herpes simplex viral thymidine kinase with host DNA polymerase alpha in mouse LP1-1 cells.

A DNA polymerase alpha-associated multienzyme complex isolated from mouse LP1-1 cells transfected with the thymidine kinase gene of herpes simplex virus type I (1) showed activities of DNA polymerase alpha, topoisomerase II, and thymidine kinase (TK) in the complex. TK antiserum recognized a 43 kDa polypeptide only in the fraction of the multienzyme complex prepared from the LP1-1 cells but not that from L-M(TK-) cells. In permeabilized cells, hydroxyurea did not show any inhibitory effect on either DNA polymerase or TK, whereas aphidicolin, novobiocin, and TK antiserum inhibited both enzymes. These results provide evidence for the functional association and an allosteric interaction between the viral TK and host DNA polymerase alpha.