Document Type


Publication Title

Nucleic Acids Research


The VP16 protein of herpes simplex virus is a potent transcriptional activator of the viral immediate early genes. The transcriptional activation region of VP16 can be divided into two functional subregions, here designated VP16N (comprising amino acids 413-456) and VP16C (amino acids 450-490). Assays of VP16C mutants resulting from both random and alanine-scanning mutagenesis indicated that the sidechains of three phenylalanines (at positions 473, 475 and 479) and one acidic residue (glutamate 476) are important for transcriptional activation. Aromatic and bulky hydrophobic amino acids were effective substitutes for each of the three Phe residues, whereas replacement with smaller or polar amino acids resulted in loss of transcriptional function. In contrast, many changes were tolerated for Glu476, including bulky hydrophobic and basic amino acids, indicating that the negative charge at this position contributes little to the function of this subregion. Similar relative activities for most of the mutants were observed in yeast and in mammalian cells, indicating that the structural requirements for this activation region are comparable in these two species. These results reinforce the hypothesis that bulky hydrophobic residues, not acidic residues, are most critical for the activity of this 'acidic' transcriptional activation region.

First Page


Last Page




Publication Date


Included in

Genetics Commons



To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.