RNase H activity: Structure, specificity, and function in reverse transcription
نویسندگان
چکیده
منابع مشابه
The mechanism of RNase H activity in DNA repair and reverse transcription
RNases H are nucleases that cleave ribonucleotides in RNA/DNA hybrid duplexes. Two classes of these enzymes have been described — RNases H1 and RNases H2. The first requires a stretch of at least four ribonucleotides in the hybrid for the cleavage to occur. In addition to its cellular form it also exists as a domain of reverse transcriptases — enzymes converting single-stranded RNA to double-st...
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Biochemical characteristics of the RNase H activity associated with immunoaffinity purified human immunodeficiency virus (HIV) reverse transcriptase (RT) were examined. Glycerol gradient centrifugation of HIV RT resulted in a single peak of RNase H, associated with RT activity, with an apparent molecular weight of 110,000. HIV RNase H exhibited a marked substrate preference for poly(dC).[3H]pol...
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In the presence of Mn2+, reverse transcriptase of both human immunodeficiency virus and murine leukemia virus hydrolyzes duplex RNA. However, designating this novel activity RNase D conflicts with Escherichia coli RNase D, which participates in tRNA processing. On the basis of its location in the RNase H domain, we propose that this novel retroviral activity be redesignated RNase H*.
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Retroviral RNases H are similar in sequence and structure to Escherichia coli RNase HI and yet have differences in substrate specificities, metal ion requirements, and specific activities. Separation of reverse transcriptase (RT) into polymerase and RNase H domains yields an active RNase H from murine leukemia virus (MuLV) but an inactive human immunodeficiency virus (HIV) RNase H. The "handle ...
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Asp(443) and Glu(478) are essential active site residues in the RNase H domain of human immunodeficiency virus type 1 (HIV-1) reverse transcriptase (RT). We have investigated the effects of substituting Asn for Asp(443) or Gln for Glu(478) on the fidelity of DNA-dependent DNA synthesis of phylogenetically diverse HIV-1 RTs. In M13mp2 lacZα-based forward mutation assays, HIV-1 group M (BH10) and...
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ژورنال
عنوان ژورنال: Virus Research
سال: 2008
ISSN: 0168-1702
DOI: 10.1016/j.virusres.2007.12.007