The GAL4 protein of Saccharomyces cerevisiae is one of the most thoroughly characterized transcriptional activators. As the N-terminal 147 amino acid residues of GAL4 are sufficient to mediate specific and strong binding to DNA, but are incapable of efficient transcriptional activation, this protein fragment has frequently been used to confer specific DNA binding in experiments examining transcriptional activation functions of heterologous proteins. This approach is facilitated by the finding that higher eukaryotes lack endogenous proteins that enhance transcription from the consensus GAL4-binding site. Fusions between GAL4 (amino acids 1-147) and activating domains from a variety of transcriptional regulatory proteins can activate transcription in yeast, plant, insects and mammalian cells. Fields and coworkers have taken advantage of these findings by the development of a unique “two-hybrid” system using GAL4 fusions in yeast to identify specific protein-protein interactions.
Function:
This protein is a positive regulator for the gene expression of the galactose-induced genes such as GAL1, GAL2, GAL7, GAL10, and MEL1 which encode for the enzymes used to convert galactose to glucose. It recognizes a 17 base pair sequence in (5'-CGGRNNRCYNYNCNCCG-3') the upstream activating sequence (UAS-G) of these genes. Subunit structure: Binds DNA as a homodimer. Interacts directly with the mediator subunits GAL11/MED15 and SRB4/MED17. Domain: The 9aaTAD motif (residues 862 to 870) is a transactivation domain present in a large number of yeast and animal transcription factors. Post-translational modification: Association between GAL11 and GAL4 may serve to expedite phosphorylation of GAL4.
Subunit:
Binds DNA as a homodimer. Interacts directly with the mediator subunits GAL11/MED15 and SRB4/MED17.
Subcellular Location:
Nuclear
Post-translational modifications:
Association between GAL11 and GAL4 may serve to expedite phosphorylation of GAL4.
Similarity:
Contains 1 Zn(2)-C6 fungal-type DNA-binding domain.
SWISS:
P04386
Gene ID:
855828
Database links:
Entrez Gene: 855828 Saccharomyces cerevisiae
SwissProt: P04386 Saccharomyces cerevisiae
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