Analysis of the varicella-zoster virus IE62 N-terminal acidic transactivating domain and its interaction with the human mediator complex.
The varicella-zoster virus major transactivator, IE62, contains a potent N-terminal acidic transcriptional activation domain (TAD). Our experiments revealed that the minimal IE62 TAD encompasses amino acids (aa) 19 to 67. We showed that the minimal TAD interacts with the human Mediator complex. Site-specific mutations revealed residues throughout the minimal TAD that are important for both activation and Mediator interaction. The TAD interacts directly with aa 402 to 590 of the MED25 subunit, and site-specific TAD mutations abolished this interaction. Two-dimensional nuclear magnetic resonance spectroscopy revealed that the TAD is intrinsically unstructured. Our studies suggest that transactivation may involve the TAD adopting a defined structure upon binding MED25.
Departments of Microbiology and Immunology, University at Buffalo SUNY, Buffalo, New York 14214, USA.
Shinobu
S
Yamamoto
Alexander
A
Eletsky
Thomas
T
Szyperski
John
J
Hay
William T
WT
Ruyechan
D000595:Amino Acid Sequence; D001665:Binding Sites; D014645:Herpesvirus 3, Human / Q000378:metabolism*; D006801:Humans; D017874:Immediate-Early Proteins / Q000378:metabolism*; D056892:Mediator Complex; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D009154:Mutation; D017433:Protein Structure, Secondary; D015534:Trans-Activators / Q000378:metabolism*; D015533:Transcriptional Activation; D014759:Viral Envelope Proteins / Q000378:metabolism*
C074221:IE62 protein, Human herpesvirus 3; D017874:Immediate-Early Proteins; C483045:MED25 protein, human; D056892:Mediator Complex; D015534:Trans-Activators; D014759:Viral Envelope Proteins