THE ACTIVATION DOMAIN OF SIMIAN IMMUNODEFICIENCY VIRUS SIVMAC239 REV PROTEIN IS STRUCTURALLY AND FUNCTIONALLY ANALOGOUS TO THE HIV-1 REV ACTIVATION DOMAIN

The Rev proteins of primate immunodeficiency viruses are essential tra nsactivators for the switch from early to late phase in the viral repl ication cycle. By mutational analysis, a putative activation domain (A D) has been assigned to the carboxy-terminus. This leucine-rich stretc h of amino acids proved to be essential for the transactivating proper ties of HIV-1 Rev. Some mutants in the AD transdominantly inhibit the function of wild-type Rev protein very efficiently. We identified a si milar domain structure for SIVmac239 Rev by sequence comparison and in vitro mutagenesis. The leucine/isoleucine residues of the SIVmac239 R ev activation domain appeared to be of similar importance for function . The mutants of these residues in the SIV AD displayed a dominant neg ative phenotype on both HIV-1 and SIVmac 239 rev-responsive elements ( RRE). The prokaryotically expressed wild-type and mutant proteins were analyzed for RNA-binding properties in a gel-shift assay in vitro. Th is assay revealed a similar binding pattern of wild-type and transdomi nant proteins on either RRE. (C) 1995 Academic Press, Inc.