A minor fraction of base J in kinetoplastid nuclear DNA is bound by the J-binding protein 1
A minor fraction of base J in kinetoplastid nuclear DNA is bound by the J-binding protein 1
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DOI：
10.1016/j.molbiopara.2005.05.001
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发表时间：
2005-09-01
影响因子：
1.5
通讯作者：
Borst, P
中科院分区：
文献类型：
--
作者：
Toaldo, CB;Kieft, R;Borst, P
The nuclear DNA of kinetoplastids contains the unusual base β-D-glucosylhydroxymethyluracil, called J for short, replacing about 0.1% of the thymine residues mainly in repetitive sequences [1–6]. Synthesis of J occurs at the DNA level probably in two steps: a thymidine hydroxylase converts thymine into hydroxymethyluracil (HMU) at specific positions in the DNA and in a second step this base is glucosylated by a glucosyl transferase [7, 8]. The enzymes responsible for this modification have not yet been identified and this has complicated the identification of the function of J, which remains a matter of speculation.Extracts of several kinetoplastids contain a J-binding protein that specifically binds to J-containing duplex DNA [9–11]. J-Binding Protein 1 (JBP1) is essential in Leishmania [12], but dispensable in Trypanosoma brucei. A knock out of JBP1 in T. brucei has no detectable effect on growth, gene expression, VSG switching or repeat stability, but drastically lowers the J content [13], indicating that JBP1 is involved in the maintenance of J in the genome.
