title: Comparative NMR studies demonstrate profound differences between two viroporins: p7 of HCV and Vpu of HIV-1.
abstract: The p7 protein from hepatitis C virus and the Vpu protein from HIV-1 are members of the viroporin family of small viral membrane proteins. It is essential to determine their structures in order to obtain an understanding of their molecular mechanisms and to develop new classes of anti-viral drugs. Because they are membrane proteins, it is challenging to study them in their native phospholipid bilayer environments by most experimental methods. Here we describe applications of NMR spectroscopy to both p7 and Vpu. Isotopically labeled p7 and Vpu samples were prepared by heterologous expression in bacteria, initial isolation as fusion proteins, and final purification by chromatography. The purified proteins were studied in the model membrane environments of micelles by solution NMR spectroscopy and in aligned phospholipid bilayers by solid-state NMR spectroscopy. The resulting structural findings enable comparisons to be made between the two proteins, demonstrating that they have quite different architectures. Most notably, Vpu has one trans-membrane helix and p7 has two trans-membrane helices; in addition, there are significant differences in the structures and dynamics of their internal loop and terminal regions.
authors: Department of Chemistry and Biochemistry, University of California, San Diego, Lajolla, CA 92093, USA.
authors: Gabriel A
authors: GA
authors: Cook
authors: Hua
authors: H
authors: Zhang
authors: Sang Ho
authors: SH
authors: Park
authors: Yan
authors: Y
authors: Wang
authors: Stanley J
authors: SJ
authors: Opella
mesh_terms: D015497:HIV-1 / Q000737:chemistry*; D016174:Hepacivirus / Q000737:chemistry*; D054298:Human Immunodeficiency Virus Proteins / Q000737:chemistry*; D007473:Ion Channels / Q000737:chemistry; D008051:Lipid Bilayers; D008823:Micelles; D008958:Models, Molecular; D019906:Nuclear Magnetic Resonance, Biomolecular; D018272:Porins / Q000737:chemistry*; D011993:Recombinant Fusion Proteins / Q000737:chemistry; D014764:Viral Proteins / Q000737:chemistry*; D054334:Viral Regulatory and Accessory Proteins / Q000737:chemistry*; D000086082:Viroporin Proteins
chemical_list: D054298:Human Immunodeficiency Virus Proteins; D007473:Ion Channels; D008051:Lipid Bilayers; D008823:Micelles; D018272:Porins; D011993:Recombinant Fusion Proteins; D014764:Viral Proteins; D054334:Viral Regulatory and Accessory Proteins; C088369:p7 protein, Hepatitis C virus; D000086082:Viroporin Proteins; C514859:vpu protein, Human immunodeficiency virus 1