Proteolytic release and crystallization of the RNase H domain of human immunodeficiency virus type 1 reverse transcriptase

• Published in: The Journal of biological chemistry 1991-08, Vol.266 (22), p.14697-14702
• Main Authors: Z Hostomska, D A Matthews, J F Davies, 2nd, B R Nodes, Z Hostomsky
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Analytical, structural and metabolic biochemistry; Base Sequence; Biological and medical sciences; Crystallization; Electrophoresis, Polyacrylamide Gel; Endoribonucleases - chemistry; Enzymes and enzyme inhibitors; Fundamental and applied biological sciences. Psychology; HIV-1 - enzymology; Hydrolysis; Molecular Sequence Data; Mutagenesis; Ribonuclease H; RNA-Directed DNA Polymerase - chemistry; Transferases; X-Ray Diffraction
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1016/S0021-9258(18)98742-9

The RNase H domain of human immunodeficiency virus type 1 (HIV-1) reverse transcriptase was released from recombinant DHFR-RNase H fusion protein by the action of HIV-1 protease and crystallized as large trigonal prisms that diffract x-rays to at least 2.4-A resolution. The protease cleavage occurred 18 residues away from the Phe440-Tyr441 site reported to be processed during maturation of the reverse transcriptase heterodimer. Mutagenesis of the protease-sensitive region (residues 430-440), which is part of the crystallized domain, indicates that any alteration of the wild-type sequence results in increased proteolysis of the p66 subunit. A model of asymmetric processing in HIV-1 reserve transcriptase which involves partial unfolding of the RNase H domain is proposed based on these results and the recently reported three-dimensional structure of this domain.