A novel type of single-stranded nucleic acid binding protein recognizing a highly frequent motif in the intergenic regions of Trypanosoma cruzi
A novel type of single-stranded nucleic acid binding protein recognizing a highly frequent motif in the intergenic regions of Trypanosoma cruzi
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DOI：
10.1016/s0006-291x(03)01561-4
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发表时间：
2003-09-12
影响因子：
3.1
通讯作者：
Garat, B
中科院分区：
文献类型：
--
作者：
Duhagon, MA;Dallagiovanna, B;Garat, B
调节痤疮表达锥虫尚未得到很好的理解。基因被组织在由基因间区域分隔的长的多顺反子转录单位中，所述基因间区域可能包含用于核酸加工的信号传导信息。多聚二核苷酸在这些区域中是常见的，并且已经被提出参与基因表达的调节。以前，我们已经报道了[dT-dG]是高度频繁的，不对称的链分布，并构成特异性蛋白结合的靶标[Biochem. Biophys.通信资源287（2001）98]。在这里，我们提出了一种新型的单链核酸结合蛋白（Tc 38）的纯化和表征，该蛋白特异性地识别这种寄生虫中的聚[dT-dG]基序。该蛋白质的推导分子量为38 kDa，其显著特征包括等电点为9.34，高频率的Ser，Leu和二氨基酸。在数据库搜索中既不能检测到组成保守域，也不能检测到结构保守域。将重组Tc 38表达为GST融合蛋白，纯化，并通过电泳迁移率变动分析用于分析靶特异性。蛋白质的不寻常的特性与特异性核酸靶点的独特特征一起表明存在可能参与锥虫基因表达机制的新事件。(C)2003爱思唯尔公司All rights reserved.
Regulation of acne expression in trypanosomatids is not yet well understood. Genes are organized in long polycistronic transcriptional units separated by intergenic regions that may contain the signaling information for nucleic acid processing. Polydinucleotides are frequent in these regions and have been proposed to be involved in regulation of gene expression. Previously, we have reported that [dT-dG] are highly frequent, asymmetrically strand distributed, and constitute targets for specific protein binding [Biochem. Biophys. Res. Commun. 287 (2001) 98]. Here, we present the purification and characterization of a new type of single stranded nucleic acid binding protein (Tc38) that recognizes specifically the motif poly[dT-dG] in this parasite. The protein has a deduced molecular weight of 38 kDa and its salient characteristics include an isoelectric point of 9.34, a high frequency of Ser, Leu, and di-amino acids. Neither compositional nor architectural conserved domains could be detected in database searches. Recombinant Tc38 was expressed as a GST fusion protein, purified, and used to analyze target specificity by electrophoretic mobility shift assays. The unusual characteristics of the protein together with the peculiar features of the specific nucleic acid target suggest the existence of a novel event that may be involved in the mechanisms of gene expression in trypanosomatids. (C) 2003 Elsevier Inc. All rights reserved.