ABSTRACT
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.
Subject(s)
DNA-Binding Proteins/biosynthesis , Herpesvirus 4, Human/chemistry , Trans-Activators/biosynthesis , Viral Proteins/biosynthesis , Crystallization/methods , Crystallography, X-Ray , DNA-Binding Proteins/chemistry , DNA-Binding Proteins/isolation & purification , Escherichia coli/metabolism , Immediate-Early Proteins/chemistry , Immediate-Early Proteins/isolation & purification , Peptide Fragments/chemistry , Protein Structure, Quaternary , Trans-Activators/chemistry , Trans-Activators/isolation & purification , Viral Proteins/chemistry , Viral Proteins/isolation & purificationABSTRACT
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.
Subject(s)
B-Lymphocytes/metabolism , DNA-Binding Proteins/metabolism , Endocytosis , Trans-Activators/metabolism , Viral Proteins/metabolism , B-Lymphocytes/virology , Cell Line , Cell Membrane/metabolism , Cell Nucleus/metabolism , Humans , Microscopy, Confocal , Protein Binding , Protein TransportABSTRACT
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.
