J. Biol. Chem., Vol. 261, Issue 22, 10218-10227, 08, 1986
The adenovirus DNA binding protein and adenovirus DNA polymerase interact to catalyze elongation of primed DNA templates
JO Lindenbaum, J Field and J Hurwitz
The adenovirus-encoded 140-kDa DNA polymerase (Ad Pol) and the 59-kDa DNA
binding protein (Ad DBP) are both required for the replication of viral DNA
in vivo and in vitro. Previous studies demonstrated that, when
poly(dT).oligo(dA) was used as a template-primer, both proteins were
required for poly(dA) synthesis. In this report, the interaction between
the Ad Pol and Ad DBP was further investigated using poly(dT).oligo(dA) as
well as a linear duplex molecule containing 3' poly(dT) tails. DNA
synthesis with the tailed template required Ad Pol, Ad DBP, and an
oligo(dA) primer hydrogen bonded to the poly(dT) tails. Incorporation was
stimulated 8-10-fold by ATP; however, no evidence of ATP hydrolysis to ADP
was observed. Synthesis was initiated at either end of the tailed molecule
and proceeded through the duplex region to the end of the molecule. This
ability to translocate through duplex DNA and to synthesize long poly(dA)
chains suggests that the Ad Pol.Ad DBP complex can act efficiently in the
elongation reactions involved in the replication of Ad DNA (both type I and
type II). During the replication reaction, substantial hydrolysis of
deoxynucleoside triphosphates to the corresponding deoxynucleoside
monophosphates occurred. This reaction required DNA synthesis and most
likely reflects an idling reaction similar to that observed with other DNA
polymerases containing 3'----5' exonuclease activity in which the
polymerase first incorporates and then hydrolyzes a dNMP.