1uph | pdb_00001uph

HIV-1 MYRISTOYLATED MATRIX

spinqualitylabelsall models 1uph, 20 NMR models Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1uph is a 1 chain structure with sequence from Viruses. Full experimental information is available from OCA. For a guided tour on the structure components use FirstGlance. NonStd Res: MYR Related: 1a43, 1a8o, 1afv, 1ak4, 1aum, 1baj, 1gds, 1gdy, 1gdz, 1gwp, 1hiw, 1l6n, 2hmx Resources: FirstGlance, OCA, RCSB, PDBsum Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMed The myristoylated matrix protein (myr-MA) of HIV functions as a regulator of intracellular localization, targeting the Gag precursor polyprotein to lipid rafts in the plasma membrane during virus assembly and dissociating from the membrane during infectivity for nuclear targeting of the preintegration complex. Membrane release is triggered by proteolytic cleavage of Gag, and it has, until now, been believed that proteolysis induces a conformational change in myr-MA that sequesters the myristyl group. NMR studies reported here reveal that myr-MA adopts myr-exposed [myr(e)] and -sequestered [myr(s)] states, as anticipated. Unexpectedly, the tertiary structures of the protein in both states are very similar, with the sequestered myristyl group occupying a cavity that requires only minor conformational adjustments for insertion. In addition, myristate exposure is coupled with trimerization, with the myristyl group sequestered in the monomer and exposed in the trimer (K(assoc) = 2.5 +/- 0.6 x 10(8) M(-2)). The equilibrium constant is shifted approximately 20-fold toward the trimeric, myristate-exposed species in a Gag-like construct that includes the capsid domain, indicating that exposure is enhanced by Gag subdomains that promote self-association. Our findings indicate that the HIV-1 myristyl switch is regulated not by mechanically induced conformational changes, as observed for other myristyl switches, but instead by entropic modulation of a preexisting equilibrium. Entropic switch regulates myristate exposure in the HIV-1 matrix protein.,Tang C, Loeliger E, Luncsford P, Kinde I, Beckett D, Summers MF Proc Natl Acad Sci U S A. 2004 Jan 13;101(2):517-22. Epub 2003 Dec 29. PMID:14699046 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Gag polyprotein

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