Genomic and cDNA actin sequences from a virulent strain of Entamoeba histolytica.
Genomic and cDNA actin sequences from a virulent strain of Entamoeba histolytica.
复制标题
溶组织内阿米巴强毒株的基因组和 cDNA 肌动蛋白序列。
DOI：
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发表时间：
1987
影响因子：
11.1
通讯作者：
N. Agabian
中科院分区：
文献类型：
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作者：
U. Edman;I. Meza;N. Agabian
引起急性阿米巴病的溶组织内阿米巴菌株的侵袭性特征是与细胞运动和肌动蛋白功能相关的攻击行为。对溶组织内阿米巴肌动蛋白基因的分析是通过设计分离生物活性核酸的方法开始的，该方法允许制备 cDNA 和基因组 DNA 文库。使用异源肌动蛋白探针，从强毒 HM1:IMSS 菌株制备的文库中分离出了编码溶组织内阿米巴肌动蛋白的 cDNA 和基因组克隆。对三个独立 cDNA 克隆和一个基因组克隆的核苷酸序列分析揭示了溶组织内阿米巴肌动蛋白中高度不寻常的密码子偏倚和不存在插入序列。该基因组克隆的编码序列与三个 cDNA 克隆中的两个相同。这些代表了至少两种不同的 mRNA，其差异仅在于蛋白质编码序列中的五个沉默变化。肌动蛋白基因的多个基因组拷贝可以通过Southern杂交来检测。溶组织内阿米巴肌动蛋白与细胞质肌动蛋白的同源性高于与肌肉肌动蛋白的同源性。尽管该蛋白质已被证明不与 DNase I 结合，但推断的氨基酸序列表明参与这种结合的所有残基都是保守的。
Invasiveness of Entamoeba histolytica strains that cause acute amoebiasis is characterized by aggressive behavior associated with cell motility and actin function. Analysis of actin genes from E. histolytica was initiated by devising methods for the isolation of biologically active nucleic acids, which allowed the preparation of cDNA and genomic DNA libraries. E. histolytica actin-encoding cDNAs and genomic clones have been isolated from libraries prepared from the virulent HM1:IMSS strain using a heterologous actin probe. Nucleotide sequence analysis of three independent cDNA clones and one genomic clone reveals a highly unusual codon bias and the absence of intervening sequences in E. histolytica actin. The coding sequence of the genomic clone is identical to that of two of the three cDNA clones. These represent at least two distinct mRNAs differing only by five silent changes in the protein coding sequence. Multiple genomic copies of the actin gene can be detected by Southern hybridization. E. histolytica actin exhibits a higher degree of homology to cytoplasmic than to muscle actin. Although the protein has been shown not to bind DNase I, the inferred amino acid sequence indicates conservation of all residues implied to participate in this binding.