title: Identification and analysis of the start site of ribosomal RNA transcription of Entamoeba histolytica.
abstract: In this article we report the identification of the start site of ribosomal RNA transcription unit of the enteric parasite E. histolytica. We cloned the upstream region of the ribosomal RNA and we defined the 5' boundary of the transcription unit with nuclear run-on assays. We report that ribosomal transcription starts 2447 bp upstream the SSU ribosomal gene, at an adenosine residue. This data was supported both by S1 mapping and by primer extension analysis; that the mapped site was indeed the transcription start point was demonstrated by RNAse protection of the in vitro capped RNA. Our sequence data around the transcription start point shows two different tandem repeat clusters immediately downstream from the transcription start point.
authors.affiliation: Departamento de Genética y Fisiología Molecular, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, México.
authors.forename: B
authors.initials: B
authors.lastname: Michel
authors.forename: P M
authors.initials: PM
authors.lastname: Lizardi
authors.forename: A
authors.initials: A
authors.lastname: Alagón
authors.forename: M
authors.initials: M
authors.lastname: Zurita
mesh_terms: D000818:Animals; D001483:Base Sequence; D001665:Binding Sites / Q000235:genetics; D003001:Cloning, Molecular; D016054:DNA, Protozoan / Q000235:genetics; D004275:DNA, Ribosomal / Q000235:genetics; D004748:Entamoeba histolytica / Q000235:genetics*; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D011401:Promoter Regions, Genetic; D012322:RNA Precursors / Q000235:genetics; D016053:RNA, Protozoan / Q000235:genetics*; D012335:RNA, Ribosomal / Q000235:genetics*; D012091:Repetitive Sequences, Nucleic Acid; D015183:Restriction Mapping; D014158:Transcription, Genetic
chemical_list: D016054:DNA, Protozoan; D004275:DNA, Ribosomal; D012322:RNA Precursors; D016053:RNA, Protozoan; D012335:RNA, Ribosomal