Johnson M S, McClure M A, Feng D F, Gray J, Doolittle R F
Proc Natl Acad Sci U S A. 1986 Oct;83(20):7648-52. doi: 10.1073/pnas.83.20.7648.
A computer analysis of the amino acid sequences from the putative gene products of retroviral pol genes has revealed a 150-residue segment that is homologous with the ribonuclease H of Escherichia coli. The segment occurs at the carboxyl terminus of the region assigned to the 90-kDa reverse transcriptase polypeptide. In contrast, a section nearer the amino terminus of this sequence can be aligned with nonretroviral polymerases. The order of activities in the pol gene is thus: polymerase-ribonuclease-endonuclease. On another note, all retroviral endonuclease sequences contain a consensus zinc-binding "finger." This should not be confused with the well-known zinc requirement of reverse transcriptases.
对逆转录病毒pol基因推定的基因产物的氨基酸序列进行的计算机分析显示，有一个150个残基的片段与大肠杆菌的核糖核酸酶H同源。该片段出现在指定为90 kDa逆转录酶多肽区域的羧基末端。相比之下，该序列中靠近氨基末端的一段可以与非逆转录病毒聚合酶比对。因此，pol基因中的活性顺序为：聚合酶-核糖核酸酶-内切核酸酶。另一方面，所有逆转录病毒内切核酸酶序列都包含一个共有锌结合“指”结构。这不应与逆转录酶众所周知的锌需求相混淆。
