Musatovova O, Alderete J F
Department of Microbiology, The University of Texas Health Science Center, 7703 Floyd Curl Dr., San Antonio, TX, 78284-7758, USA.
Microb Pathog. 1998 Apr;24(4):223-39. doi: 10.1006/mpat.1997.0199.
Trichomonas vaginalisis a flagellated protozoan responsible for the most common non-viral sexually transmitted disease. The immunogen P270 was previously found to be up-regulated in expression and to undergo phenotypic variation between surface versus cytoplasmic localization in trichoImonads harbouring a dsRNA virus. In this report, we characterize the entire p270 open reading frame (ORF) and the unknown flanking 5;- and 3;-unique, non-repeat coding sequences of the gene in addition to untranslated regions. Consistent with an earlier report (Dailey & Alderete, 1991, Infect. Immun. 59: 2083-88), a significant portion of the gene consists of a tandemly repeated 333 bp element that contains the sequence coding for the epitope DREGRD detected by murine monoclonal antibody and antibody from the sera of patients. The non-repeat coding regions for the 5;- and 3;-ends were 69 nucleotides (23 amino acids) and 1183 nucleotides (395 amino acids), respectively. Sequencing of repeat elements showed them to be identical, affirming the highly-conserved nature of this element throughout the gene. The start codon was immediately preceded by the 12 nucleotide consensus sequence (TCATTTTTAATA) found in other trichomonad protein-coding genes. A very AT-rich, non-coding region was identified upstream of the p270 ORF. P270 appears to contain a leader sequence at the amino-terminus and transmembrane domain at the carboxy-terminus. No significant homology was found with any reported proteins at either the nucleotide or amino acid level.
阴道毛滴虫是一种有鞭毛的原生动物，可引发最常见的非病毒性性传播疾病。免疫原P270先前被发现其表达上调，并且在携带双链RNA病毒的滴虫中，其在表面与细胞质定位之间会发生表型变异。在本报告中，我们对整个p270开放阅读框（ORF）以及该基因未知的侧翼5′-和3′-独特非重复编码序列以及非翻译区进行了表征。与早期报告（Dailey和Alderete，1991年，《感染与免疫》59: 2083 - 88）一致，该基因的很大一部分由一个333 bp的串联重复元件组成，该元件包含由鼠单克隆抗体和患者血清抗体检测到的表位DREGRD的编码序列。5′-和3′-末端的非重复编码区分别为69个核苷酸（23个氨基酸）和1183个核苷酸（395个氨基酸）。重复元件的测序表明它们是相同的，证实了该元件在整个基因中具有高度保守的性质。起始密码子紧接在其他滴虫蛋白质编码基因中发现的12个核苷酸的共有序列（TCATTTTTAATA）之前。在p270 ORF上游鉴定出一个富含AT的非编码区。P270似乎在氨基末端含有一个前导序列，在羧基末端含有一个跨膜结构域。在核苷酸或氨基酸水平上，未发现与任何已报道蛋白质有显著同源性。
