Illimaquinone, a selective inhibitor of the RNase H activity of human immunodeficiency virus type 1 reverse transcriptase.

We studied the effect of the natural marine substance illimaquinone on the catalytic activities of reverse transcriptase from human immunodeficiency virus type 1. Illimaquinone inhibited the RNase H activity of the enzyme at concentrations of 5 to 10 microgram/ml, whereas RNA-dependent DNA polymerase and DNA-dependent DNA polymerase activities were considerably less susceptible to this inhibition. Two synthetic derivatives of illimaquinone, in which the 6'-hydroxyl group at the ortho position to one of carbonyl groups of the quinone ring was modified, proved ineffective in inhibiting the human immunodeficiency virus type 1 reverse transcriptase RNase H function, suggesting involvement of the 6'-hydroxyl group in blocking the enzymatic activity.