Anatomy of the primase-alpha DNA polymerase reaction accomplished by nucleoprotein complexes harboring an extrachromosomal DNA identical with avian myeloblastosis virus core-bound DNA: influencing by carbonyldiphosphonate, mimosine and butylphenyl deoxyguanosine-5 '-triphosphate

Activities of the primase (Pr)-alpha DNA polymerase (pol) enzyme complex be longing to the naturally occurring reaction systems represented by special NP complexes harboring an extrachromosomal DNA identical with avian myelobl astosis virus (AMV) core-bound DNA (J. Riman. A. Sulova and K. Horska, Acta virol 39, 149-159 (1995); J. Riman and A. Sulova, Acta virol 41, 181-192 ( 1997)) were studied in the absence and presence of carbonyldiphosphonate (C OMDP), mimosine (MIMO), to it related ciclopirox olamine (CPX) and butylphe nyl deoxyguanosine-5'-triphosphate (BuPdGTP). Reaction products radioactive ly labeled for RNA and DNA and synthesized with the common four ribonucleos ide triphosphates (rNTPs) or rNTPs and deoxyribonucleoside triphosphates (d NTPs) in the reaction medium, were analyzed by polyacrylamide gel electroph oresis (PAGE) at denaturing conditions. It was shown that COMDP strongly ac tivates the Pr and uncouples its activity from that of alpha DNA pol with a ccumulation of initiator (i) RNAs of the basic length. This phenomenon is n ot affected by BuPdGTP. MIMO, in contrast, stimulates both pot activities o f this enzyme complex and preserves their mutual coupling. The effects of C OMDP, MIMO and CPX seem to be modulated by concentration of the ambient dNT Ps. Addition of dNTPs to rNTPs makes the effects of COMDP and MIMO mutually exclusive, suggesting that both these agents, though chemically quite diff erent, are competing for one active site responsible for coupling these bot h pol activities into the one Pr-alpha DNA pol reaction.