Human cytomegalovirus-associated DNA polymerase and protein kinase activities

J Gen Virol. 1981 Nov;57(Pt 1):149-56. doi: 10.1099/0022-1317-57-1-149.

Abstract

Human cytomegalovirus (HCMV), purified exclusively from the extracellular media, contained a DNA polymerase activity in addition to a protein kinase activity. The DNA polymerase expressed its maximum activity in the presence of 5 to 10 mM-MgCl2. The enzyme was able to use effectively activated calf thymus DNA, poly(dA).oligo(dT)12--18 and poly(dC).oligo(dG)12--18 as the template primers. The DNA polymerizing activity was eluted with 0.18 to 0.2 M-KCl from a phosphocellulose column. It was relatively resistant to phosphonoacetic acid inhibition even at a high concentration of 100 micrograms/ml with activated calf thymus DNA as the template primer, but the DNA polymerase activity was totally suppressed at this concentration when poly(dA).oligo(dT)12--18 was used as the template primer. The enzyme activity was inhibited by ammonium sulphate at 0.01 to 0.3 M with either activated calf thymus DNA or poly(dA).oligo(dT)12--18 as the template primer. The protein kinase has maximum activity in the presence of 10 to 20 mM-MgCl2, and preferred virion proteins as phospho-acceptor to protamine sulphate. Histone, caesin and bovine serum albumin (BSA) were found to be poor substrates. The phosphorylated protein pattern of the in vivo [32P]orthophosphate-labelled virions was not identical to that of the in vitro phosphorylated Nonidet P40-dissociated virions, although seven phosphorylated polypeptides did co-migrate in SDS--polyacrylamide gel electrophoresis (SDS--PAGE). Procedures known to solubilize virions showed that the DNA polymerase and protein kinase were internal components of the virion.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Ammonium Sulfate / pharmacology
  • Cytomegalovirus / enzymology*
  • DNA / metabolism
  • DNA-Directed DNA Polymerase / metabolism*
  • Humans
  • Magnesium / metabolism
  • Magnesium Chloride
  • Phosphonoacetic Acid / pharmacology
  • Polydeoxyribonucleotides / metabolism
  • Protein Kinases / metabolism*
  • Substrate Specificity
  • Templates, Genetic

Substances

  • Polydeoxyribonucleotides
  • Magnesium Chloride
  • DNA
  • Protein Kinases
  • DNA-Directed DNA Polymerase
  • Magnesium
  • Phosphonoacetic Acid
  • Ammonium Sulfate