Document 0526
 DOCN  M9650526
 TI    Effect of human immunodeficiency virus type 1 (HIV-1) nucleocapsid
       protein on HIV-1 reverse transcriptase activity in vitro.
 DT    9605
 AU    Ji X; Klarmann GJ; Preston BD; Department of Biochemistry, University of
       Utah, Salt Lake City; 84112, USA.
 SO    Biochemistry. 1996 Jan 9;35(1):132-43. Unique Identifier : AIDSLINE
       MED/96134828
 AB    Conversion of human immunodeficiency virus type 1 (HIV-1) genomic RNA to
       viral DNA is a requisite step in the virus life cycle. This conversion
       is catalyzed by reverse transcriptase (RT) associated with a large
       nucleoprotein complex composed of several viral proteins including
       nucleocapsid (NC). To better characterize the biochemical mechanisms of
       viral DNA synthesis, we overexpressed and purified recombinant HIV-1 NC
       and studied its effect on the activity and processivity of HIV-1 RT
       during polymerization of HIV-1 template sequences in vitro. The effect
       of NC on steady-state RT activity was dependent on the order of addition
       of reaction components. Addition of NC prior to formation of
       RT-primer.template-dNTP ternary complexes inhibited primer extension and
       reduced total product yields by slowing steady-state RT turnover. In
       contrast, addition of NC to preformed ternary complexes resulted in
       efficient primer extension and increased RT processivity at specific DNA
       template sites. NC stimulated polymerization (2-4 times) through eight
       of 13 sites examined in the cRRE region of HIV-1 env and increased the
       rate of polymerization through the D3/CTS region of HIV-1 pol 10 times.
       The data suggest that NC affects RT processivity by facilitating
       polymerization through regions of template secondary structure. Thus, NC
       functions as a single-strand binding (SSB)-like accessory replication
       factor for RT in vitro and may be part of a multicomponent retroviral
       replication complex.
 DE    Base Sequence  Binding Sites  Capsid/*PHARMACOLOGY  DNA Primers
       Electrophoresis, Polyacrylamide Gel  Human  HIV-1/*METABOLISM
       Macromolecular Systems  Molecular Sequence Data  Molecular Weight
       Polymerase Chain Reaction  Recombinant Proteins/CHEMISTRY/ISOLATION &
       PURIF/METABOLISM  RNA-Directed DNA Polymerase/CHEMISTRY/ISOLATION &
       PURIF/  *METABOLISM  Support, Non-U.S. Gov't  Support, U.S. Gov't,
       P.H.S.  Templates  Viral Core Proteins/*PHARMACOLOGY  JOURNAL ARTICLE

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