RESUMO
A C-terminal fragment of the Epstein-Barr virus immediate-early transcription factor ZEBRA has been expressed as a recombinant protein in Escherichia coli and purified to homogeneity. The fragment behaves as a dimer in solution, consistent with the presence of a basic region leucine-zipper (bZIP) domain. Crystals of the fragment in complex with a DNA duplex were grown by the hanging-drop vapour-diffusion technique using polyethylene glycol 4000 and magnesium acetate as crystallization agents. Crystals diffract to better than 2.5 A resolution using synchrotron radiation (lambda = 0.976 A). Crystals belong to space group C2, with unit-cell parameters a = 94.2, b = 26.5, c = 98.1 A, beta = 103.9 degrees.
Assuntos
Proteínas de Ligação a DNA/biossíntese , Herpesvirus Humano 4/química , Transativadores/biossíntese , Proteínas Virais/biossíntese , Cristalização/métodos , Cristalografia por Raios X , Proteínas de Ligação a DNA/química , Proteínas de Ligação a DNA/isolamento & purificação , Escherichia coli/metabolismo , Proteínas Imediatamente Precoces/química , Proteínas Imediatamente Precoces/isolamento & purificação , Fragmentos de Peptídeos/química , Estrutura Quaternária de Proteína , Transativadores/química , Transativadores/isolamento & purificação , Proteínas Virais/química , Proteínas Virais/isolamento & purificaçãoRESUMO
A number of viral proteins have the property to penetrate into the cells when present in the extra-cellular compartment. Here, we report that the Epstein-Barr virus (EBV) transcriptional activator EB1/Zta, which is responsible for the activation of the EBV lytic replication, binds to lymphoid cells surface, is efficiently translocated and accumulates in the nucleus. The internalization of EB1/Zta is energy-dependent and shares common features with endocytosis. As the EB1/Zta was not degraded in the cells and reached the nucleus, the potential effect of its internalisation on viral reactivation was assessed.
Assuntos
Linfócitos B/metabolismo , Proteínas de Ligação a DNA/metabolismo , Endocitose , Transativadores/metabolismo , Proteínas Virais/metabolismo , Linfócitos B/virologia , Linhagem Celular , Membrana Celular/metabolismo , Núcleo Celular/metabolismo , Humanos , Microscopia Confocal , Ligação Proteica , Transporte ProteicoRESUMO
Synthesis, physical and analytical properties of 6-alkylacylamino-4-octyl-2H-1,4-benzo-thiazin-3-ones derivatives are described. These new compounds were prepared by acylation and/or alkylation of the amino group under phase transfer catalysis conditions. Acid hydrolysis of the alkylacylamino-2H-1,4-benzo-thiazin-3-ones afforded N-alkylamino-benzothiazin-3-ones. Some of these compounds were evaluated in vitro for possible bacteriostatic activity.
