Schleiss M R
Division of Infectious Diseases, Children's Hospital Research Foundation, Cincinnati, Ohio 45229, USA.
J Gen Virol. 1995 Jul;76 ( Pt 7):1827-33. doi: 10.1099/0022-1317-76-7-1827.
Although the guinea-pig cytomegalovirus (GPCMV) displays a similar pathogenesis to human cytomegalovirus (HCMV), there have unfortunately been few molecular analyses of the GPCMV genome to date. The guinea-pig has proved useful for the testing of drugs active against CMV infection, and insights derived from characterization of the specific virally encoded molecular targets of antiviral therapies would allow this model system to be more fully developed. Because the DNA polymerase serves as an important target for nucleoside antiviral agents active against herpesviruses, experiments were undertaken to identify, clone and sequence the GPCMV DNA polymerase gene (pol). A 3285 bp ORF capable of encoding a 1094 amino acid protein was identified spanning portions of the HindIII Q and P fragments of the genome. This ORF contained extensive homology to other herpesvirus DNA pol genes. Northern blot analyses identified two 3' coterminal pol-specific mRNAs of 3.9 and 1.9 kb at early times post-infection. Primer extension and nuclease protection analyses mapped the 5' end of the 3.9 kb transcript to a site 275 bases upstream of the pol initiation codon. Comparison of the GPCMV pol-encoded sequence to those of other herpesvirus polymerases identified non-conservative amino acid substitutions in a domain involved in substrate recognition.
尽管豚鼠巨细胞病毒（GPCMV）的发病机制与人类巨细胞病毒（HCMV）相似，但遗憾的是，迄今为止对GPCMV基因组的分子分析很少。豚鼠已被证明可用于测试对CMV感染有效的药物，而对抗病毒疗法中特定病毒编码分子靶点的表征所获得的见解将使这个模型系统得到更充分的发展。由于DNA聚合酶是抗疱疹病毒核苷类抗病毒药物的重要靶点，因此开展了实验以鉴定、克隆和测序GPCMV DNA聚合酶基因（pol）。在基因组的HindIII Q和P片段的部分区域中鉴定出一个3285 bp的开放阅读框（ORF），其能够编码一个1094个氨基酸的蛋白质。该ORF与其他疱疹病毒DNA pol基因具有广泛的同源性。Northern印迹分析在感染后早期鉴定出两个3' 共末端的pol特异性mRNA，大小分别为3.9 kb和1.9 kb。引物延伸和核酸酶保护分析将3.9 kb转录本的5' 末端定位到pol起始密码子上游275个碱基处的一个位点。将GPCMV pol编码序列与其他疱疹病毒聚合酶的序列进行比较，发现在参与底物识别的结构域中存在非保守氨基酸取代。
