title: Initiation by RNA polymerase II and formation of runoff transcripts containing unblocked and unmethylated 5' termini.
abstract: Transcription of cloned adenovirus, beta-globin, and retrovirus long terminal repeat DNAs in HeLa whole-cell lysate was inhibited by S-adenosylhomocysteine. However, full-length 1.7-kilobase transcripts made on adenovirus 2 late promoter DNA contained 5'-terminal GpppA, consistent with specific initiation and runoff synthesis in the absence of product methylation. Formation of runoff transcripts including retrovirus RNAs that normally contain 5'-m7GpppGmpC was not decreased by replacing GTP with non-hydrolyzable analogs, and Rous-associated virus-2 runoff products made in the presence of GTP-gamma-S contained 5'-terminal gamma-S-pppGpC. The results indicate that capping and specific transcript synthesis by RNA polymerase II are not obligatorily linked in HeLa whole-cell lysate. Accurate initiation is dependent on ATP hydrolysis, and in contrast to GTP, replacement of ATP by 5'-adenylyl-imidodiphosphate blocked specific initiation of transcripts that start with either GTP (Rous-associated virus-2, Rous-associated virus-0) or ATP (beta-globin, adenovirus).
mesh_terms: D000260:Adenoviruses, Human / Q000235:genetics*; D000266:Adenylyl Imidodiphosphate / Q000494:pharmacology; D001483:Base Sequence; D003001:Cloning, Molecular; D005914:Globins / Q000235:genetics*; D016244:Guanosine 5'-O-(3-Thiotriphosphate); D006160:Guanosine Triphosphate / Q000031:analogs & derivatives / Q000032:analysis; D006165:Guanylyl Imidodiphosphate / Q000494:pharmacology; D006367:HeLa Cells / Q000378:metabolism; D006801:Humans; D008745:Methylation; D010957:Plasmids; D012319:RNA Polymerase II / Q000378:metabolism*; D013873:Thionucleotides / Q000032:analysis; D014158:Transcription, Genetic / Q000187:drug effects
chemical_list: D013873:Thionucleotides; D000266:Adenylyl Imidodiphosphate; D006165:Guanylyl Imidodiphosphate; D016244:Guanosine 5'-O-(3-Thiotriphosphate); D006160:Guanosine Triphosphate; D005914:Globins; D012319:RNA Polymerase II