       Document 0333
 DOCN  M9630333
 TI    First glimpses at structure-function relationships of the nucleocapsid
       protein of retroviruses.
 DT    9603
 AU    Darlix JL; Lapadat-Tapolsky M; de Rocquigny H; Roques BP; LaboRetro,
       Unite de Virologie humaine INSERM U412, Ecole Normale; Superieure de
       Lyon, France.
 SO    J Mol Biol. 1995 Dec 8;254(4):523-37. Unique Identifier : AIDSLINE
       MED/96102278
 AB    Retroviruses are a family of widespread small animal viruses about 110
       nm in diameter, composed of an inner core surrounded by an outer
       envelope formed of a lipid bilayer of cellular origin in which are
       anchored viral glycoproteins. The inner core is formed by an outer shell
       of capsid protein molecules (CA protein) surrounding the dimeric RNA
       genome in close association with about 2000 molecules of nucleocapsid
       protein (NC protein) and molecules of reverse transcriptase (RT) and
       integrase (IN). Conversion of the genomic single-stranded RNA into a
       double-stranded proviral DNA by RT takes place in the nucleocapsid
       substructure and involves two DNA strand transfers to generate the long
       terminal repeats (LTR) required for IN-mediated integration of the
       proviral DNA into the cellular genome and its expression. In this review
       we have summarized some of the properties and functions of the
       nucleocapsid protein of the most intensely studied oncoretroviruses
       (MuLV and ASLV) and lentiviruses (HIV-1). Recent biochemical and genetic
       data on retroviral NC proteins have shown that this small viral protein
       endowed with a strong affinity for nucleic acids exhibits nucleic acid
       annealing and strand transfer activities and is required for the
       formation of infectious viral particles. These new activities of NC
       protein are most probably necessary at the early steps of proviral DNA
       synthesis. The 3-D structures of HIV-1 and MoMuLV NC proteins, deduced
       from NMR studies, are characterized by a central globular domain with
       one (MoMuLV) or two (HIV-1) zinc fingers. This should facilitate a
       rational approach of new anti-HIV therapies based on inhibition of NC
       protein functions. Due to space limitations and the very abundant
       literature on retroviruses, references to articles prior to the
       publication of the second volume of RNA Tumor Viruses in 1985 (Weiss et
       al., 1985) will be minimal. We also direct the reader to an excellent
       review which summarizes recent insights into biochemical and structural
       aspects of the retroviral enzymes PR, RT and IN (Katz & Skalka, 1994).
 DE    Amino Acid Sequence  Capsid/*CHEMISTRY/METABOLISM/*PHYSIOLOGY  Models,
       Molecular  Molecular Sequence Data  Nucleic Acids/METABOLISM
       Retroviridae/*CHEMISTRY  RNA, Transfer  RNA, Viral  Structure-Activity
       Relationship  Support, Non-U.S. Gov't  Transcription, Genetic  Viral
       Core Proteins/*CHEMISTRY/METABOLISM/*PHYSIOLOGY  JOURNAL ARTICLE  REVIEW
       REVIEW, TUTORIAL

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

