Mutagenesis of Gln294 of the reverse transcriptase of human immunodeficiency virus type‐2 and its effects on the ribonuclease H activity

Bochner, Ron; Duvshani, Amit; Adir, Noam; Hizi, Amnon

doi:10.1016/j.febslet.2008.07.010

Cited by 6 publications

(9 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…When the Gln was replaced by a Pro, either in both HIV-2 RT subunits or only in the smaller subunit, the resulting HIV-2 RT showed an about tenfold increase in its RNase H activity in comparison to the wildtype RT [39,40]. Interestingly, changing Gln294 of HIV-2 RT p55 to residues that represent all amino acid groups (except for a Gln) has also resulted in an increase in the RNase H activity [120]. The interactions between the polymerase and the RNase H domains may be particularly important in the case of HIV-1 and HIV-2 RTs, since the expression of the smaller subunit of the RTs (p51 and p55, respectively), which lacks the entire RNase H domain, results in an enzyme with a very low DNA polymerase activity [16,121].…”

Section: The Rnase H Activity Of Rtmentioning

confidence: 99%

Retroviral reverse transcriptases

Herschhorn

Hizi

2010

Cell. Mol. Life Sci.

107

111

View full text Add to dashboard Cite

Reverse transcription is a critical step in the life cycle of all retroviruses and related retrotransposons. This complex process is performed exclusively by the retroviral reverse transcriptase (RT) enzyme that converts the viral single-stranded RNA into integration-competent double-stranded DNA. Although all RTs have similar catalytic activities, they significantly differ in several aspects of their catalytic properties, their structures and subunit composition. The RT of human immunodeficiency virus type-1 (HIV-1), the virus causing acquired immunodeficiency syndrome (AIDS), is a prime target for the development of antiretroviral drug therapy of HIV-1/AIDS carriers. Therefore, despite the fundamental contributions of other RTs to the understanding of RTs and retrovirology, most recent RT studies are related to HIV-1 RT. In this review we summarize the basic properties of different RTs. These include, among other topics, their structures, enzymatic activities, interactions with both viral and host proteins, RT inhibition and resistance to antiretroviral drugs.

show abstract

Section: The Rnase H Activity Of Rtmentioning

confidence: 99%

Retroviral reverse transcriptases

Herschhorn

Hizi

2010

Cell. Mol. Life Sci.

107

111

View full text Add to dashboard Cite

show abstract

“…In the HIV-1 RT, the same protein surface area has a positive charge and presents a Pro in the 294 residue [33]. Interestingly, when the HIV-1 RT 294 Pro residue is mutated in Gln the HIV-1 RNase H activity is reduced and, conversely, when the HIV-2 RT 294 Gln residue is mutated in Pro the HIV-2 RNase H activity is 10 fold increased [32,33]. The observation that mutations in the small subunit strongly influences RT activities clearly confirms the fine interplay between the two subunits and the importance of the overall enzyme architecture which has been also demonstrated by other several studies, including also the ones on HIV-1 RT drug resistance [6,34].…”

Section: Hiv-2 Rnase Hmentioning

confidence: 87%

“…It is also worth to highlight that, beside the 10-fold difference between the RNase H activity of HIV-1 and HIV-2, both viruses effectively replicate raising the question whether it is the HIV-2 that has a low level of RNase H function or it is the HIV-1 which has an high level of enzyme activity [27]. However, the fact that it has been reported that the great majority (if not all) of the HIV-2 isolates present the Gln in position 294 [32] seems to substantiate the latter hypothesis.…”

Section: Hiv-2 Rnase Hmentioning

confidence: 93%

“…During viral replication the HIV-2 RT carries out all the functions and reactions described for the HIV-1 RT (including the cleavage patterns) [29] with the remarkable differences that the HIV-2 RT-associated RNase H activity is 10-fold lower than the HIV-1 RNase H activity [30,31]. The major determinant of this difference has been identified to be the Gln294 residue in the small subunit, which lies in a negative surface area and influences the enzyme affinity for the RNA:DNA substrate while it does not alter its processivity [32]. In the HIV-1 RT, the same protein surface area has a positive charge and presents a Pro in the 294 residue [33].…”

Section: Hiv-2 Rnase Hmentioning

confidence: 98%

See 1 more Smart Citation

HIV-1 RT-Associated RNase H Function Inhibitors: Recent Advances in Drug Development

Tramontano

Santo

2010

CMC

View full text Add to dashboard Cite

The HIV-1 genomic RNA reverse transcription is an essential step in the virus cycle carried out by the viral-coded reverse transcriptase (RT), which has two associated functions: the RNA- and DNA-dependent DNA polymerase (RDDP and DDDP) function and the ribonuclease H (RNase H) function. The RNase H function catalyzes the selective hydrolysis of the RNA strand of the RNA:DNA heteroduplex replication intermediate. The RT associated activities are both essential for HIV-1 replication and validated targets for drug development, but only the polymerase function has been widely investigated as drug target. In fact, either nucleoside or non-nucleoside RT inhibitors currently used in therapy act on the polymerase associated activity. In this review, we describe the compounds, reported up to today, which inhibit the HIV-1 RNase H function, their chemical structures, the structure-activity relationships and the mechanism of action.

show abstract

“…(iv) RNase H. This assay was performed as described earlier by us (17)(18)(19)25). Each assay contained ϳ0.1 pmol of the 5=-32 P-end-labeled RNA transcript (E11), which was annealed to 0.4 pmol of a 20mer synthetic oligonucleotide DNA (E10 in Table 1).…”

Section: Methodsmentioning

confidence: 99%

A Novel Leu92 Mutant of HIV-1 Reverse Transcriptase with a Selective Deficiency in Strand Transfer Causes a Loss of Viral Replication

Herzig

Voronin

Kucherenko

et al. 2015

J Virol

View full text Add to dashboard Cite

The process of reverse transcription (RTN) in retroviruses is essential to the viral life cycle. This key process is catalyzed exclusively by the viral reverse transcriptase (RT) that copies the viral RNA into DNA by its DNA polymerase activity, while concomitantly removing the original RNA template by its RNase H activity. During RTN, the combination between DNA synthesis and RNA hydrolysis leads to strand transfers (or template switches) that are critical for the completion of RTN. The balance between these RT-driven activities was considered to be the sole reason for strand transfers. Nevertheless, we show here that a specific mutation in HIV-1 RT (L92P) that does not affect the DNA polymerase and RNase H activities abolishes strand transfer. There is also a good correlation between this complete loss of the RT's strand transfer to the loss of the DNA clamp activity of the RT, discovered recently by us. This finding indicates a mechanistic linkage between these two functions and that they are both direct and unique functions of the RT (apart from DNA synthesis and RNA degradation). Furthermore, when the RT's L92P mutant was introduced into an infectious HIV-1 clone, it lost viral replication, due to inefficient intracellular strand transfers during RTN, thus supporting the in vitro data. As far as we know, this is the first report on RT mutants that specifically and directly impair RT-associated strand transfers. Therefore, targeting residue Leu92 may be helpful in selectively blocking this RT activity and consequently HIV-1 infectivity and pathogenesis. IMPORTANCEReverse transcription in retroviruses is essential for the viral life cycle. This multistep process is catalyzed by viral reverse transcriptase, which copies the viral RNA into DNA by its DNA polymerase activity (while concomitantly removing the RNA template by its RNase H activity). The combination and balance between synthesis and hydrolysis lead to strand transfers that are critical for reverse transcription completion. We show here for the first time that a single mutation in HIV-1 reverse transcriptase (L92P) selectively abolishes strand transfers without affecting the enzyme's DNA polymerase and RNase H functions. When this mutation was introduced into an infectious HIV-1 clone, viral replication was lost due to an impaired intracellular strand transfer, thus supporting the in vitro data. Therefore, finding novel drugs that target HIV-1 reverse transcriptase Leu92 may be beneficial for developing new potent and selective inhibitors of retroviral reverse transcription that will obstruct HIV-1 infectivity. R everse transcription (RTN) is a critical step in the life cycle of all retroviruses and the related long terminal repeat (LTR) retrotransposons. This complex multistep process is performed by a single enzyme, the retroviral reverse transcriptase (RT) that copies the viral plus strand RNA into integration competent double-stranded viral DNA (1-3). To perform RTN, RTs have two activities. These are the DNA polymerase activity, which co...

show abstract

Mutagenesis of Gln294 of the reverse transcriptase of human immunodeficiency virus type‐2 and its effects on the ribonuclease H activity

Cited by 6 publications

References 26 publications

Retroviral reverse transcriptases

Retroviral reverse transcriptases

HIV-1 RT-Associated RNase H Function Inhibitors: Recent Advances in Drug Development

A Novel Leu92 Mutant of HIV-1 Reverse Transcriptase with a Selective Deficiency in Strand Transfer Causes a Loss of Viral Replication

Contact Info

Product

Resources

About