Structural highlights
FunctionGCN4_YEAST Is a transcription factor that is responsible for the activation of more than 30 genes required for amino acid or for purine biosynthesis in response to amino acid or purine starvation. Binds and recognize the DNA sequence: 5'-TGA[CG]TCA-3'. Publication Abstract from PubMedCoiled-coil sequences in proteins consist of heptad repeats containing two characteristic hydrophobic positions. The role of these buried hydrophobic residues in determining the structures of coiled coils was investigated by studying mutants of the GCN4 leucine zipper. When sets of buried residues were altered, two-, three-, and four-helix structures were formed. The x-ray crystal structure of the tetramer revealed a parallel, four-stranded coiled coil. In the tetramer conformation, the local packing geometry of the two hydrophobic positions in the heptad repeat is reversed relative to that in the dimer. These studies demonstrate that conserved, buried residues in the GCN4 leucine zipper direct dimer formation. In contrast to proposals that the pattern of hydrophobic and polar amino acids in a protein sequence is sufficient to determine three-dimensional structure, the shapes of buried side chains in coiled coils are essential determinants of the global fold. A switch between two-, three-, and four-stranded coiled coils in GCN4 leucine zipper mutants.,Harbury PB, Zhang T, Kim PS, Alber T Science. 1993 Nov 26;262(5138):1401-7. PMID:8248779[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences | ||||||||||||||||||||
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