HUMAN-IMMUNODEFICIENCY-VIRUS REVERSE-TRANSCRIPTASE - ISOLATION AND SUBSTRATE-SPECIFICITY

The isolation of human immunodeficiency virus (HIV) reverse transcriptase produced in bacteria [E. coli RRi strain (pRC-RT, pRK248cIts)] is described. Substrate properties of 2'-deoxyribonucleoside 5'-triphosphate analogs studied previously in cell-free systems with avian myeloblastosis virus and Moloney murine leukemia virus reverse transcriptases were examined in vitro with HIV reverse transcriptase. The substrate properties of new 2'-deoxyadenosine 5'-triphosphate analogs-2',3'-dideoxy-2',3'-didehydro- and 2',3'-dideoxytubercidin 5'-triphosphates-were examined. The relative efficiency of incorporation of different 2'-deoxyribonucleoside 5'-triphosphate analogs into the DNA chain was evaluated. It was shown that HIV reverse transcriptase cloned in E. call and purified by the described method exhibits selectivity toward various 2'-deoxyribonucleoside 5'-triphosphates that is characteristic of the previously studied reverse transcriptases including the native viral one. This property permits the employment of the cloned enzyme in different model systems.