title: beta-D-glucosyl-hydroxymethyluracil: a novel modified base present in the DNA of the parasitic protozoan T. brucei.
abstract: We have previously shown that the DNA of the unicellular eukaryote T. brucei contains about 0.1% of a novel modified base, called J. The presence of J correlates with a DNA modification associated with the silencing of telomeric expression sites for the variant surface antigens of trypanosomes. Here we show that J is 5-((beta-D-glucopyranosyloxy)-methyl)-uracil (shortened to beta-D-glucosyl-hydroxymethyluracil), a base not previously found in DNA. We discuss putative pathways for the introduction of this base modification at specific positions in the DNA and the possible contribution of this modification to repression of surface antigen gene expression.
authors.affiliation: Division of Molecular Biology, The Netherlands Cancer Institute, Amsterdam.
authors.forename: J H
authors.initials: JH
authors.lastname: Gommers-Ampt
authors.forename: F
authors.initials: F
authors.lastname: Van Leeuwen
authors.forename: A L
authors.initials: AL
authors.lastname: de Beer
authors.forename: J F
authors.initials: JF
authors.lastname: Vliegenthart
authors.forename: M
authors.initials: M
authors.lastname: Dizdaroglu
authors.forename: J A
authors.initials: JA
authors.lastname: Kowalak
authors.forename: P F
authors.initials: PF
authors.lastname: Crain
authors.forename: P
authors.initials: P
authors.lastname: Borst
mesh_terms: D000818:Animals; D002853:Chromatography, Liquid; D002855:Chromatography, Thin Layer; D016054:DNA, Protozoan / Q000737:chemistry* / Q000302:isolation & purification; D003854:Deoxyribonucleotides / Q000302:isolation & purification; D004591:Electrophoresis, Polyacrylamide Gel; D005700:Galactosyltransferases; D008401:Gas Chromatography-Mass Spectrometry; D015870:Gene Expression; D005960:Glucosides / Q000032:analysis* / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D016615:Telomere / Q000502:physiology; D014346:Trypanosoma brucei brucei / Q000737:chemistry* / Q000235:genetics; D014498:Uracil / Q000031:analogs & derivatives* / Q000032:analysis / Q000737:chemistry; D014643:Variant Surface Glycoproteins, Trypanosoma / Q000096:biosynthesis
chemical_list: D016054:DNA, Protozoan; D003854:Deoxyribonucleotides; D005960:Glucosides; D014643:Variant Surface Glycoproteins, Trypanosoma; C084880:5-((glucopyranosyloxy)methyl)uracil; D014498:Uracil; D005700:Galactosyltransferases