Document 0116
 DOCN  M9460116
 TI    Rous sarcoma virus integrase protein: mapping functions for catalysis
       and substrate binding.
 DT    9404
 AU    Bushman FD; Wang B; Infectious Disease Laboratory, Salk Institute, La
       Jolla,; California 92037.
 SO    J Virol. 1994 Apr;68(4):2215-23. Unique Identifier : AIDSLINE
       MED/94187061
 AB    Rous sarcoma virus (RSV), like all retroviruses, encodes an integrase
       protein that is responsible for covalently joining the
       reverse-transcribed viral DNA to host DNA. We have probed the
       organization of functions within RSV integrase by constructing mutant
       derivatives and assaying their activities in vitro. We find that
       deletion derivatives lacking the amino-terminal 53 amino acids, which
       contain the conserved H-X(3-7)-H-X(23-32)-C-X(2)-C (HHCC) Zn(2+)-binding
       motif, are greatly impaired in their ability to carry out two reactions
       characteristic of integrase proteins: specific cleavage of the viral DNA
       termini and DNA strand transfer. Deletion mutants lacking the
       carboxyl-terminal 69 amino acids are also unable to carry out these
       reactions. However, all deletion mutants that retain the central domain
       are capable of carrying out disintegration, an in vitro reversal of the
       normal DNA strand transfer reaction, indicating that the catalytic
       center probably lies within this central region. Another conserved
       motif, D-X(39-58)-D-X(35)-E, is found in this central domain. These
       findings with RSV integrase closely parallel previous findings with
       human immunodeficiency virus integrase, indicating that a modular
       catalytic domain is a general feature of this family of proteins.
       Surprisingly, and unlike results obtained so far with human
       immunodeficiency virus integrase, efficient strand transfer activity can
       be restored to a mutant RSV integrase lacking the amino-terminal HHCC
       domain by fusion to various short peptides. Furthermore, these fusion
       proteins retain the substrate specificity of RSV integrase. These data
       support a model in which the integrase activities required for strand
       transfer in vitro, including substrate recognition, multimerization, and
       catalysis, all lie primarily outside the amino-terminal HHCC domain.
 DE    Amino Acid Sequence  Base Sequence  Comparative Study  DNA Mutational
       Analysis  DNA Nucleotidyltransferases/*GENETICS/METABOLISM  DNA,
       Viral/*METABOLISM  HIV/ENZYMOLOGY  Molecular Sequence Data  Recombinant
       Proteins/METABOLISM  Recombination, Genetic  Sarcoma Viruses,
       Avian/*ENZYMOLOGY  Sequence Deletion  Substrate Specificity  Support,
       Non-U.S. Gov't  Support, U.S. Gov't, P.H.S.  *Virus Integration  JOURNAL
       ARTICLE

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