FIG. 1.

The molecular rheostat model for the accumulation of Rev on the RRE. One model for Rev function suggests that Rev initially binds to the RBE whereas subsequent Revs oligomerize along an adjacent, imperfectly paired duplex in stem I (38, 58). In this model, the overall architecture of the RRE complex plays a critical role in sequestering multiple Rev molecules. The RRE is drawn and numbered according to Mann et al. (38). Rev protein molecules are represented as oblongs; the actual number and alignment of Revs on the RRE is unknown.