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目的研究广州地区人巨细胞病毒(HCMV)临床低传代分离株UL143基因的多态性。方法对3株经多重PCR鉴定的HCMV临床低传代分离株进行HCMVUL143基因全序列扩增,扩增产物克隆到pMD18-T载体上测序,并将其序列与GenBank中公布的其它临床分离株UL143基因一起进行分析。结果D3株UL143基因因碱基缺失形成多处终止密码无法产生有功能的蛋白;Toledo株UL143基因开放读码框由279个核苷酸组成,编码蛋白由92个氨基酸残基组成;其它临床分离株UL143基因开放读码框均由252个核苷酸组成,DNA序列比较保守,变异均为碱基替换,编码蛋白由83个氨基酸残基组成,氨基酸序列也很保守,不同临床分离株氨基酸变异率为1.2%～2.4%;HCMVUL143蛋白翻译后修饰位点在除Toledo株之外的所有分离株中均高度保守,没有缺失或新增;不同临床分离株UL143蛋白二级结构有所不同;除Toledo株外,其余分离株UL143蛋白的等电点均为8.75。结论临床低传代分离株HCMVUL143基因DNA及其编码产物的氨基酸序列极为保守,但仍存在一定多态性。
Objective To study the polymorphism of the UL143 gene of human low cytomegalovirus (HCMV) isolates in Guangzhou area. Methods HCMVUL143 gene was amplified by PCR from three HCMV clinical isolates identified by multiplex PCR. The amplified product was cloned into pMD18-T vector and sequenced. The sequence of the HCMVUL143 gene was sequenced and compared with other published clinical isolates of UL143 Analyze together. Results The gene of UL143 in D3 strain was unable to produce functional protein due to the deletion of its base. The open reading frame of Toledo strain UL143 gene consisted of 279 nucleotides and the encoded protein consisted of 92 amino acid residues. Other clinical isolates The open reading frame (ORF) of strain UL143 was composed of 252 nucleotides. The DNA sequence was conserved. The mutations were all base substitutions. The encoded protein consisted of 83 amino acid residues and the amino acid sequence was very conservative. The amino acid variation of different clinical isolates The rate of 1.2% ~ 2.4%; HCMVUL143 protein posttranslational modification sites in all isolates except Toledo were highly conservative, no deletion or addition; different clinical isolates UL143 protein secondary structure is different; except Toledo isolates, the isolates of the other isolates UL143 protein were 8.75. Conclusion The amino acid sequence of HCMVUL143 gene and its encoded product in clinical isolates are very conservative, but some polymorphisms still exist.