Secondary structure of a leucine zipper determined by nuclear magnetic resonance spectroscopy.
Previous work has shown that a synthetic peptide corresponding to the leucine zipper region of the yeast transcriptional activator GCN4 forms a stable dimer of alpha-helices and that the helices are oriented in a parallel manner. Two-dimensional nuclear magnetic resonance spectroscopy (NMR) is used here to demonstrate that the helix is continuous for at least 32 of the 33 residues in the peptide. The results also indicate that the dimer is symmetric. It is therefore unlikely that the interdigitation model for the structure of leucine zippers is correct, since interdigitation of leucine residues in a parallel dimer would lead to an asymmetric structure. The data are consistent with a coiled-coil structure.
Oas
T G
TG
Whitehead Institute for Biomedical Research, Cambridge, Massachusetts 02142.
McIntosh
L P
LP
O'Shea
E K
EK
Dahlquist
F W
FW
Kim
P S
PS
D000595:Amino Acid Sequence; D004268:DNA-Binding Proteins; D005656:Fungal Proteins; D007700:Kinetics; D007930:Leucine; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008961:Models, Structural; D008969:Molecular Sequence Data; D010455:Peptides / Q000138:chemical synthesis; D011487:Protein Conformation; D011494:Protein Kinases; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors
D004268:DNA-Binding Proteins; D005656:Fungal Proteins; D010455:Peptides; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; D011494:Protein Kinases; D007930:Leucine