TY - JOUR
T1 - The acidic activation domains of the GCN4 and GAL4 proteins are not α helical but form β sheets
AU - Van Hoy, Michael
AU - Leuther, Kerstin K.
AU - Kodadek, Thomas
AU - Johnston, Stephen A.
N1 - Funding Information:
We thank Professor Keith Wilkinson (Emory University) for his generous gift of ubiquitin-hydrolase, Dr. David Ecker (Smith Kline and French) for pNMHUb, and Professor Jeff Kelly (Texas A&M University) for helpful discussions. Professor Lila Gierasch, Dr. Zhi-Ping Liu, Dr. Josep Rizo, and Dr. Sam Landry provided expert advice on CD spectroscopy. We thank Dr. Ettore Appella for synthetic GAL4 peptide. This work was supported by grants from the National Institutes of Health (NIH) (GM47140 to T. K. and GM-40700 to S. A. J.), the Human Frontiers Science Program, the Perot Family Foundation, and the Moss Heart Trust (S. A. J.). M. V. H. was supported by an NIH Biophysics Training Grant.
PY - 1993/2/26
Y1 - 1993/2/26
N2 - The most common class of activation domains, the so-called acidic activators, has been proposed either to adopt an amphipathic α-helical structure or to exist as unstructured "acid blobs." However, genetic analysis of an acidic activation domain in the yeast GAL4 protein has suggested that the structure of the activation region is a β sheet. To distinguish between these models, we conducted a biophysical analysis of peptides corresponding to the yeast GAL4 and GCN4 acidic activation domains. Circular dichroism spectroscopy shows that the peptides are not α helical, but that they can undergo a transition to a structure that is almost 100% β sheet in character in slightly acidic solution. We also show that the articial acidic activator AH has structural properties that are markedly different from the natural GAL4 and GCN4 domains and does not adopt a β-rich structure at reduced pH.
AB - The most common class of activation domains, the so-called acidic activators, has been proposed either to adopt an amphipathic α-helical structure or to exist as unstructured "acid blobs." However, genetic analysis of an acidic activation domain in the yeast GAL4 protein has suggested that the structure of the activation region is a β sheet. To distinguish between these models, we conducted a biophysical analysis of peptides corresponding to the yeast GAL4 and GCN4 acidic activation domains. Circular dichroism spectroscopy shows that the peptides are not α helical, but that they can undergo a transition to a structure that is almost 100% β sheet in character in slightly acidic solution. We also show that the articial acidic activator AH has structural properties that are markedly different from the natural GAL4 and GCN4 domains and does not adopt a β-rich structure at reduced pH.
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U2 - 10.1016/0092-8674(93)90077-4
DO - 10.1016/0092-8674(93)90077-4
M3 - Article
C2 - 8440022
AN - SCOPUS:0027522642
SN - 0092-8674
VL - 72
SP - 587
EP - 594
JO - Cell
JF - Cell
IS - 4
ER -