Activities of a lagging DNA strand synthesis of nucleoprotein complexes harboring an extrachromosomal DNA closely related to avian myeloblastosis virus core-bound DNA.
Nucleoprotein (NP) complexes constituting the material of the postmicrosomal sediment (POMS) and its three basic components (A, B, C) (Ríman and Sulová, 1997a), harboring an extrachromosomal DNA closely related to AMV DNA were found to possess DNA- and RNA-synthesizing activities (SAs) reflecting the ability of this material to be intensely labelled for DNA and RNA, respectively. The types of these NA-SAs were compatible with those significant for a lagging DNA strand synthesis (LSS). The use of selective inhibitors and of the proliferating cell nuclear antigen (PCNA) disclosed a successive involvement of alpha DNA polymerase (pol) and PCNA-insensitive delta DNA pol in LSS. In this respect, we show gradual changes in the representation of activities (As) of both mentioned DNA pols in the NP complexes of the individual POMS components. Those of POMS component C contained alpha DNA pol As only, while a distinct portion of DNA SAs of POMS component B was represented on expense of alpha DNA pol As by PCNA-insensitive delta DNA pol (epsilon DNA pol), As which represented practically all the DNA SAs of POMS component A. The type of RNA SAs of this material represented mostly by primase (Pr) As corresponded well with the nature of LSS. An exception was represented by a minor portion of RNA-SAs of POMS component A which was alpha amanitin-sensitive like RNA pol II. Moreover, analyzing this natural model replication system, we found that the carbonyldiphosphonate (COMDP), a selective inhibitor of the PCNA-insensitive delta DNA pol, was a strong activator of Pr-As and/or Pr-alpha DNA pol As of NP complexes of POMS component C.
Ríman
J
J
Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, Prague, Czech Republic.
Sulová
A
A
D016590:Aphidicolin / Q000494:pharmacology; D009189:Avian Myeloblastosis Virus / Q000235:genetics*; D004257:DNA Polymerase II / Q000037:antagonists & inhibitors; D019915:DNA Primase / Q000378:metabolism; D004279:DNA, Viral / Q000096:biosynthesis* / Q000378:metabolism; D003848:Deoxyguanine Nucleotides / Q000494:pharmacology; D004164:Diphosphonates / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D019384:Nucleic Acid Synthesis Inhibitors; D009698:Nucleoproteins / Q000378:metabolism*; D018809:Proliferating Cell Nuclear Antigen / Q000494:pharmacology; D013698:Templates, Genetic; D014758:Viral Core Proteins / Q000378:metabolism
D004279:DNA, Viral; D003848:Deoxyguanine Nucleotides; D004164:Diphosphonates; D004791:Enzyme Inhibitors; D019384:Nucleic Acid Synthesis Inhibitors; D009698:Nucleoproteins; D018809:Proliferating Cell Nuclear Antigen; D014758:Viral Core Proteins; C062324:carbonyldiphosphonate; D016590:Aphidicolin; C040364:N(2)-(4-n-butylphenyl)-2'-deoxyguanosine 5'-triphosphate; D019915:DNA Primase; D004257:DNA Polymerase II