Cloning and characterization of a novel histone acetyltransferase homologue from the protozoan parasite Toxoplasma gondii reveals a distinct GCN5 family member
Cloning and characterization of a novel histone acetyltransferase homologue from the protozoan parasite Toxoplasma gondii reveals a distinct GCN5 family member
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DOI：
10.1016/s0378-1119(99)00526-0
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发表时间：
2000-01-25
期刊：
影响因子：
3.5
通讯作者：
Smith, CK
中科院分区：
文献类型：
--
作者：
Sullivan, WJ;Smith, CK
为了鉴定顶复门寄生虫中参与转录调控的基因产物，对刚地弓形虫表达序列标签（EST）数据库中含有与已知转录组分相似性的序列进行了检查。一个EST（dbEST ID #466792）与酵母GCN 5和其他组蛋白乙酰转移酶（HAT）表现出很强的相似性。根据EST序列设计引物，从T.从弓形虫速殖子cDNA文库中筛选出4个cDNA克隆。利用5' RACE和基因组测序技术，获得了3.5kb的完整开放阅读框架（ORF）。推导的编码区的氨基酸序列表明，C-末端结构域具有明确的相似性，GCN 5家族成员。然而，与其他低等真核生物不同，T.弓形虫GCN 5具有延长的N-末端结构域，其长度与后生动物HAT蛋白相似，但组成不同。这些特征使T. GCN 5是GCN 5家族的一个新成员。用cDNA序列的一部分作为探针，从T. gondii基因组文库，产生类似于GCN 5基因座的7.5kb图谱，其包含由6个内含子分隔的7个外显子。Southern分析验证了预测的图谱，并表明类似的基因座可能存在于基因组的其他地方。(C)2000 Elsevier Science B. V.保留所有权利。
In an effort to identify gene products involved in transcriptional regulation in apicomplexan parasites, the Toxoplasma gondii expressed sequence tag (EST) database was examined for sequences containing similarity to known transcriptional components. One EST (dbEST ID #466792) exhibited strong similarity to yeast GCN5 and other histone acetyltransferases (HATs). Primers were designed based on the EST sequence and used to amplify an 850 bp fragment (containing an intron) from T. gondii genomic DNA which was used to identify four cDNA clones from a tachyzoite cDNA library. The complete open reading frame (ORF) of 3.5 kb was elucidated using 5' RACE and genomic sequence. The deduced amino acid sequence of the coding region shows that the C-terminal domain possesses unequivocal similarity to GCN5 family members. However, unlike other lower eukaryotes, T. gondii GCN5 has an extended N-terminal domain similar in length, but not in composition, to metazoan HAT proteins. These features distinguish T. gondii GCN5 as a novel member of the GCN5 family. A portion of the cDNA sequence was used as a probe to isolate three overlapping clones from a T. gondii genomic library, generating a similar to 7.5 kb map of the GCN5 locus which contains seven exons separated by six introns. Southern analysis verifies the predicted map and suggests that a similar locus may be present elsewhere in the genome. (C) 2000 Elsevier Science B.V. All rights reserved.