Crouch R J
Laboratory of Molecular Genetics, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892.
New Biol. 1990 Sep;2(9):771-7.
Ribonucleases H (RNases H) from Escherichia coli and retroviruses share common features at the primary amino acid sequence and activity levels. RNase H is involved in selection of the origins of replication in E. coli and in DNA synthesis of the positive strand of retroviruses. Crystallographic studies of E. coli RNase H indicate that several amino acids, conserved in both cellular and retroviral RNases H, form an active site for hydrolysis of the RNA of RNA-DNA hybrids. Multiple forms of RNase H are present in both prokaryotes and eukaryotes. It is suggested that these RNases H may be part of larger polypeptides and, as has been shown for reverse transcriptase RNase H derived from retroviruses, that the location and/or activity of the RNase H may be influenced by other regions of the polypeptides.
来自大肠杆菌和逆转录病毒的核糖核酸酶H（RNases H）在一级氨基酸序列和活性水平上具有共同特征。核糖核酸酶H参与大肠杆菌复制起点的选择以及逆转录病毒正链的DNA合成。大肠杆菌核糖核酸酶H的晶体学研究表明，在细胞和逆转录病毒核糖核酸酶H中保守的几个氨基酸形成了一个用于水解RNA-DNA杂交体中RNA的活性位点。原核生物和真核生物中都存在多种形式的核糖核酸酶H。有人提出，这些核糖核酸酶H可能是更大多肽的一部分，并且正如从逆转录病毒衍生的逆转录酶核糖核酸酶H所显示的那样，核糖核酸酶H的位置和/或活性可能受多肽其他区域的影响。
