Characterization of a folding intermediate from HIV-1 ribonuclease H.
The RNase H domain from HIV-1 (HIV RNase H) encodes an essential retroviral activity. Refolding of the isolated HIV RNase H domain shows a kinetic intermediate detectable by stopped-flow far UV circular dichroism and pulse-labeling H/D exchange. In this intermediate, strands 1, 4, and 5 as well as helices A and D appear to be structured. Compared to its homolog from Escherichia coli, the rate limiting step in refolding of HIV RNase H appears closer to the native state. We have modeled this kinetic intermediate using a C-terminal deletion fragment lacking helix E. Like the kinetic intermediate, this variant folds rapidly and shows a decrease in stability. We propose that inhibition of the docking of helix E to this folding intermediate may present a novel strategy for anti HIV-1 therapy.
Kern
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Department of Molecular and Cell Biology, University of California, Berkeley, 94720, USA.
Handel
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Marqusee
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D002942:Circular Dichroism; D003903:Deuterium / Q000378:metabolism; D015195:Drug Design; D004791:Enzyme Inhibitors / Q000737:chemistry; D004795:Enzyme Stability / Q000187:drug effects; D019791:Guanidine / Q000494:pharmacology; D015497:HIV-1 / Q000201:enzymology*; D006859:Hydrogen / Q000378:metabolism; D007700:Kinetics; D008958:Models, Molecular; D009154:Mutation / Q000235:genetics; D011489:Protein Denaturation; D017510:Protein Folding; D017433:Protein Structure, Secondary; D016914:Ribonuclease H / Q000737:chemistry*; D014764:Viral Proteins / Q000737:chemistry
D004791:Enzyme Inhibitors; D014764:Viral Proteins; D006859:Hydrogen; D003903:Deuterium; D016914:Ribonuclease H; D019791:Guanidine