Three-dimensional structure of a simian immunodeficiency virus protease/inhibitor complex. Implications for the design of human immunodeficiency virus type 1 and 2 protease inhibitors.Zhao, B., Winborne, E., Minnich, M.D., Culp, J.S., Debouck, C., Abdel-Meguid, S.S.
(1993) Biochemistry 32: 13054-13060
- PubMed: 8241159
- PubMed Abstract:
Simian immunodeficiency virus (SIV) proteins have considerable amino acid sequence homology to those from human immunodeficiency virus (HIV); thus monkeys are considered useful models for the preclinical evaluation of acquired immune deficiency syndr ...
Simian immunodeficiency virus (SIV) proteins have considerable amino acid sequence homology to those from human immunodeficiency virus (HIV); thus monkeys are considered useful models for the preclinical evaluation of acquired immune deficiency syndrome (AIDS) therapeutics. We have crystallized and determined the three-dimensional structure of SIV protease bound to the hydroxyethylene isostere inhibitor SKF107457. Crystals of the complex were grown from 25-32% saturated sodium chloride, by the hanging drop method of vapor diffusion. They belong to the orthorhombic space group I222, with a = 46.3 A, b = 101.5 A, and c = 118.8 A. The structure has been determined at 2.5-A resolution by molecular replacement and refined to a crystallographic discrepancy factor, R (= sigma parallel Fo magnitude of - magnitude of Fc parallel/sigma magnitude of Fo magnitude of), of 0.189. The overall structure of the complex is very similar to previously reported structures of HIV-1 protease bound to inhibitors. The inhibitor is bound in a conformation that is almost identical to that found for the same inhibitor bound to HIV-1 protease, except for an overall translation of the inhibitor, varying along the backbone atoms from about 1.0 A at the termini to about 0.5 A around the scissile bond surrogate. The structures of the SIV and HIV-1 proteins vary significantly only in three surface loops composed of amino acids 15-20, 34-45, and 65-70. Superposition of the 1188 protein backbone atoms from the two structures gives an rms deviation of 1.0 A; this number is reduced to 0.6 A when atoms from the three surface loops are eliminated from the rms calculation.(ABSTRACT TRUNCATED AT 250 WORDS)
Department of Macromolecular Sciences, SmithKline Beecham, King of Prussia, Pennsylvania 19406.