ATP binding leads to autophosphorylation of HSV-1 origin binding protein

Abstract

The tsUL9 gene products exhibit a strongly reduced ATPase function at the nonpermissive temperature, an effect that can be compensated by the addition of unspecific DNA. Here it is demonstrated, that the reduced ATPase activity is caused by altered ATP binding of the tsOBP at the nonpermissive temperature. Furthermore the addition of unspecific DNA to the ATPase reaction not only compensates the ts phenotype at the nonpermissive temperature but also enhances the ATPase activity at the permissive temperature of both wild type and tsOBP. Thereby, the OBP becomes autophosphorylated. Moreover, addition of subgenomic HSV-1 DNA has no further enhancing effect, supporting the inchworm model for the HSV-OBP function.