A CONSERVED HAIRPIN STRUCTURE PREDICTED FOR THE POLY(A) SIGNAL OF HUMAN AND SIMIAN IMMUNODEFICIENCY VIRUSES

A comparative sequence analysis of part of the RNA genome containing t he poly(A) signal of different groups of immunodeficiency viruses, inc luding human types 1 and 2, simian types mandrill, african green monke y, and sykes, reveals the conservation of certain structural features despite the divergence in sequence. In all cases, the AAUAAA signal wa s found to be flanked by nucleotide segments that can basepair, thus f orming a hairpin structure with the poly(A) signal in the single-stran ded loop. The fact that both this stem-loop structure motif. Consisten t with this idea, we demonstrate that stabilization or destabilization of the stem region does severely inhibit the replication potential of the HIV-1 virus. (C) 1995 Academic Press,