Document 0122
 DOCN  M95A0122
 TI    Influence of human immunodeficiency virus nucleocapsid protein on
       synthesis and strand transfer by the reverse transcriptase in vitro.
 DT    9510
 AU    Rodriguez-Rodriguez L; Tsuchihashi Z; Fuentes GM; Bambara RA; Fay PJ;
       Department of Biochemistry, University of Rochester, School of; Medicine
       and Dentistry, New York 14642, USA.
 SO    J Biol Chem. 1995 Jun 23;270(25):15005-11. Unique Identifier : AIDSLINE
       MED/95318057
 AB    Human immunodeficiency virus (HIV) nucleocapsid protein (NC) influences
       HIV reverse transcriptase (RT) catalyzed strand transfer synthesis from
       internal regions of natural sequence RNA. In the strand transfer assay
       reaction in vitro, primer synthesis initiated on a donor template can
       transfer and be completed on an acceptor template. NC was added at
       concentrations up to twice that needed for 100% template coating. As the
       concentration of NC was increased, primer extension was stimulated until
       NC coated approximately 50% of the template. Stimulation was caused in
       part by an increase in the number of primers that sustained synthesis.
       Subsequent increments of NC decreased synthesis. The presence of NC also
       increased the efficiency of the strand transfer reaction, allowing a
       greater proportion of extended primers to transfer from donor to
       acceptor templates. Processivity of the RT on the donor template was
       measured using both challenged and enzyme dilution assays. NC did not
       alter the proportion of synthesis products that reached the end of the
       template, indicating little effect on processivity. This result suggests
       that the increase in full-length product synthesis, observed in
       reactions where the RT repeatedly bound the primer-template, resulted
       from promotion of RT reassociation by NC. Consequently, since the RT
       could not reassociate with the template in the processivity assay, NC
       could not stimulate the amount of full-length synthesis. No strand
       transfer was observed in dilution processivity assays, suggesting that
       the RT must dissociate and rebind during the transfer reaction.
       Stimulation of synthesis, e.g. by increased dNTP concentration, normally
       inhibits strand transfer. Stimulation of both synthesis and transfer by
       NC indicates that properties of NC that improve the transfer event
       prevail over the negative effects of rapid synthesis on transfer
       efficiency.
 DE    Capsid/*METABOLISM  Deoxyribonucleotides/METABOLISM  DNA,
       Viral/*BIOSYNTHESIS/ISOLATION & PURIF  Electrophoresis, Polyacrylamide
       Gel  HIV/*METABOLISM  Kinetics  Recombinant Proteins/METABOLISM  Reverse
       Transcriptase/*METABOLISM  Support, Non-U.S. Gov't  Support, U.S. Gov't,
       P.H.S.  Templates  Viral Core Proteins/*METABOLISM  JOURNAL ARTICLE

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