Lim D, Maas W K
Department of Microbiology, New York University Medical Center, New York 10016.
Cell. 1989 Mar 10;56(5):891-904. doi: 10.1016/0092-8674(89)90693-4.
We have found a branched DNA-RNA compound in E. coli B, that is similar in its secondary structure, but not its nucleotide sequence, to the previously described branched DNA-RNA compounds in myxobacteria. This compound is not produced in E. coli K12. We have cloned a 3.5 kb chromosomal segment of E. coli B, which, when transferred into E. coli K12, leads to the production of the DNA-RNA compound. We describe the isolation of the DNA-RNA compound, the determination of its nucleotide sequence, and the nucleotide sequence of the genes required for its formation. The sequence contains the coding regions for the DNA component, the RNA component, and an open reading frame encoding a reverse transcriptase. This reverse transcriptase is shown to be required for the formation of the DNA-RNA compound in vivo and in vitro.
我们在大肠杆菌B中发现了一种分支DNA-RNA化合物，其二级结构与粘细菌中先前描述的分支DNA-RNA化合物相似，但核苷酸序列不同。这种化合物在大肠杆菌K12中不产生。我们克隆了大肠杆菌B的一个3.5 kb染色体片段，将其转入大肠杆菌K12后，会导致DNA-RNA化合物的产生。我们描述了DNA-RNA化合物的分离、其核苷酸序列的测定以及其形成所需基因的核苷酸序列。该序列包含DNA成分、RNA成分的编码区域以及一个编码逆转录酶的开放阅读框。结果表明，这种逆转录酶在体内和体外形成DNA-RNA化合物时都是必需的。
