title: Adenovirus type 2 coded single-stranded DNA binding protein: in vivo phosphorylation and modification.
abstract: The adenovirus type 2-coded single-stranded DNA binding protein (DBP) was shown to be a phosphoprotein and to exist in at least two forms that differ in mobility by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. After a 30-min pulse with [35S]methionine or 32PO4, 35S- or 32P-labeled DBP had a nominal molecular weight of 74,000 whereas after a 30-min label followed by a 20-h chase, 35S- and 32P-labeled DBP had a nominal molecular weight of 77,000. Both large and small forms of 35S- and 32P-labeled DBP bound to single-stranded DNA-cellulose columns and were eluted by 0.4 to 0.6 M NaCl; both forms also were immunoprecipitated by antiserum against adenovirus type 1-simian virus 40-induced tumor cells (this antiserum contains antibodies against DBP) and by monospecific antiserum against 95 to 99% purified DBP. With highly purified 32P-DBP labeled 7 to 10 h postinfection, it was shown that the 32P radioactivity was firmly associated with protein material (i.e., not contaminating nucleic acids or phospholipids) and had properties expected of a phosphoester of an amino acid; paper electrophoresis of acid hydrolysates of this preparation identified phosphoserine but not phosphothreonine. Phosphoserine but not phosphothreonine was also identified in acid hydrolysates of another preparation of 32P-DBP labeled for 30 min, chased for 20 h, and then immunoprecipitated by adenovirus type 1-simian virus 40 antiserum.
mesh_terms: D000260:Adenoviruses, Human / Q000032:analysis / Q000378:metabolism*; D000596:Amino Acids / Q000032:analysis; D002460:Cell Line; D004277:DNA, Single-Stranded / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D010710:Phosphates / Q000378:metabolism; D010750:Phosphoproteins / Q000032:analysis / Q000378:metabolism*; D011485:Protein Binding; D014764:Viral Proteins / Q000032:analysis / Q000378:metabolism*
chemical_list: D000596:Amino Acids; D004277:DNA, Single-Stranded; D010710:Phosphates; D010750:Phosphoproteins; D014764:Viral Proteins