X-ray scattering indicates that the leucine zipper is a coiled coil.
Dimerization of the bZIP class of eukaryotic transcriptional control proteins requires a sequence motif called the leucine zipper. We have grown two distinct crystal forms of a 33-amino acid peptide corresponding to the leucine zipper of the yeast transcriptional activator GCN4. This peptide is known to form a dimer of parallel helices in solution. X-ray scattering from both crystal forms shows reflections that are diagnostic of coiled coils. The most notable reflections occur at approximately 5.2 A resolution and correspond to the pitch of helices in coiled coils. There is no diffraction maximum near 5.4 A, the characteristic pitch of straight helices. Our results provide direct evidence that the leucine zipper of GCN4 is a coiled coil.
Rasmussen
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Department of Biochemistry, University of Utah School of Medicine, Salt Lake City 84132.
Benvegnu
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O'Shea
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Kim
P S
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Alber
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D000595:Amino Acid Sequence; D003460:Crystallization; D016350:Leucine Zippers; D008969:Molecular Sequence Data; D010455:Peptides / Q000138:chemical synthesis / Q000737:chemistry*; D011487:Protein Conformation; D014961:X-Ray Diffraction
D010455:Peptides