Functional analysis of novel selective mutants of the reverse transcriptase of human immunodeficiency virus type 1
We have generated by site-directed mutagenesis plasmids that induce the synthesis of specific mutants of the reverse transcriptase (RT) of human immunodeficiency virus type 1 (HIV-1). These recombinant mutants of HIV-1 RT, designed on the basis of our previous studies of HIV-1 and HIV-2 RTs, were an...
Saved in:
Published in | The Journal of biological chemistry Vol. 267; no. 26; pp. 18255 - 18258 |
---|---|
Main Authors | , |
Format | Journal Article |
Language | English |
Published |
Bethesda, MD
American Society for Biochemistry and Molecular Biology
15.09.1992
|
Subjects | |
Online Access | Get full text |
Cover
Loading…
Summary: | We have generated by site-directed mutagenesis plasmids that induce the synthesis of specific mutants of the reverse transcriptase
(RT) of human immunodeficiency virus type 1 (HIV-1). These recombinant mutants of HIV-1 RT, designed on the basis of our previous
studies of HIV-1 and HIV-2 RTs, were analyzed for structure-function relationship by assessing their RNA-dependent and DNA-dependent
DNA polymerase as well as the ribonuclease H activities. Three groups of mutants were studied. 1) We have investigated the
importance of the only two sets of highly conserved double prolines found in the sequence of HIV-1 RT. The results indicate
that the conversion of either one or both prolines (at positions 225 and 226) to threonines have no significant effect on
all catalytic activities of the enzyme. The mutants in which prolines 419 and 420 were individually modified to threonines
exhibit full activities, whereas the double proline 419/420 mutant lost most of its RNase H activity (although the DNA polymerase
function was fully retained). 2) We have deleted phenylalanine 346 from HIV-1 RT, which is absent in wild type HIV-2 RT. This
mutant of HIV-1 RT lost practically all catalytic activities. 3) A mutant of HIV-1 RT in which a cysteine residue substituted
for alanine 446, was found to be slightly hyperactive for both DNA polymerase and RNase H activities. |
---|---|
ISSN: | 0021-9258 1083-351X |
DOI: | 10.1016/S0021-9258(19)36950-9 |