title: Identification of a promoter element located upstream from the hepatitis B virus X gene.
abstract: We have analyzed a series of plasmids in which the sequences located upstream from the hepatitis B virus (HBV) X gene were linked to the chloramphenicol acetyl transferase (CAT) gene. Expression of the marker CAT gene in transfected cells clearly demonstrated that sequences preceding the X gene contain an active promoter. RNA mapping by primer extension indicated that the RNA encoded by the X gene promoter initiates at multiple sites spanning nucleotides 1250 to 1350 on the HBV genome. Deletion within the adjacent HBV enhancer element region significantly reduced the activity of the X gene promoter, suggesting that the X gene promoter requires the enhancer element for maximal activity.
mesh_terms: D000123:Acetyltransferases / Q000235:genetics; D001483:Base Sequence; D002460:Cell Line; D015500:Chloramphenicol O-Acetyltransferase; D005796:Genes; D005814:Genes, Viral; D006515:Hepatitis B virus / Q000235:genetics*; D006801:Humans; D010957:Plasmids; D011401:Promoter Regions, Genetic; D014764:Viral Proteins / Q000235:genetics
chemical_list: D014764:Viral Proteins; D000123:Acetyltransferases; D015500:Chloramphenicol O-Acetyltransferase