Document 0627
 DOCN  M9490627
 TI    An active recombinant p15 RNase H domain is functionally distinct from
       the RNase H domain associated with human immunodeficiency virus type 1
       reverse transcriptase.
 DT    9411
 AU    Evans DB; Fan N; Swaney SM; Tarpley WG; Sharma SK; Biochemistry
       Research, Upjohn Laboratories, Kalamazoo, Michigan; 49001.
 SO    J Biol Chem. 1994 Aug 26;269(34):21741-7. Unique Identifier : AIDSLINE
       MED/94342369
 AB    An active p15 RNase H domain, consisting of amino acids 427-560 of human
       immunodeficiency virus type 1 (HIV-1) reverse transcriptase (RT) and a
       genetically engineered penta-histidine N-terminal affinity tag, was
       expressed in Escherichia coli and purified to apparent homogeneity by
       immobilized metal affinity chromatography. The purified p15 RNase H
       domain exhibited no substrate preference for [3H]poly(rG).poly(dC)
       compared to [3H]poly(rA).poly(dT), in contrast with the HIV-1
       RT-associated RNase H, which showed a 30-fold preference for the former
       substrate. Unlike the HIV-1 RT-associated RNase H, when challenged with
       unlabeled substrate, the recombinant p15 RNase H domain was relatively
       nonprocessive in RNA degradative activity of the [3H]poly(rA).poly(dT)
       duplex. Kinetic studies using p15 RNase H showed substrate inhibition
       with an apparent K(i) value of 0.12 micron for the [3H]poly(rA).poly(dT)
       hybrid. Substrate inhibition was not observed for the HIV-1
       RT-associated RNase H. The results show that the isolated p15 HIV-1
       RNase H domain is functionally distinct from the recombinant HIV-1
       RT-associated RNase H.
 DE    Amino Acid Sequence  Base Sequence  Cations, Divalent/PHARMACOLOGY
       Comparative Study  Escherichia coli/GENETICS  HIV-1/*ENZYMOLOGY
       Molecular Sequence Data  Peptide Fragments/GENETICS/*METABOLISM  Protein
       Engineering  Recombinant Proteins/METABOLISM  Reverse
       Transcriptase/ANTAGONISTS & INHIB/DRUG EFFECTS/GENETICS/  *METABOLISM
       Ribonuclease H, Calf Thymus/DRUG EFFECTS/GENETICS/*METABOLISM
       RNA/METABOLISM  Substrate Specificity  Support, U.S. Gov't, P.H.S.
       JOURNAL ARTICLE

       SOURCE: National Library of Medicine.  NOTICE: This material may be
       protected by Copyright Law (Title 17, U.S.Code).