Minimum length of a sequence-specific DNA binding peptide.
NMR experiments show that a stable complex can be formed between a 14-base-pair oligonucleotide and a disulfide-bonded dimer of a peptide containing 27 residues of the basic region of the yeast transcriptional activator GCN4; the complex is in slow exchange on the NMR time scale. In contrast, a nonspecific complex is in fast exchange on the NMR time scale. DNase I footprinting experiments show that dimers of peptides containing as few as 20 residues of GCN4 bind DNA with sequence specificity similar to that of the intact protein. Circular dichroism experiments suggest that specific binding involves only 15 residues, corresponding to residues 231-245 of GCN4, in an alpha-helical conformation. These results limit substantially the region of GCN4 involved in sequence-specific DNA contacts and provide a uniquely simple model for studying protein-DNA interactions in detail.
Talanian
R V
RV
Howard Hughes Medical Institute, Department of Biology, Massachusetts Institute of Technology, Cambridge 02142.
McKnight
C J
CJ
Rutkowski
R
R
Kim
P S
PS
D000595:Amino Acid Sequence; D001483:Base Sequence; D001665:Binding Sites; D002942:Circular Dichroism; D017362:Cyclic AMP Response Element-Binding Protein; D004247:DNA / Q000737:chemistry / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000378:metabolism*; D003850:Deoxyribonuclease I / Q000378:metabolism; D005656:Fungal Proteins / Q000378:metabolism*; D046911:Macromolecular Substances; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000378:metabolism; D011487:Protein Conformation; D011494:Protein Kinases; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors / Q000378:metabolism*
D017362:Cyclic AMP Response Element-Binding Protein; D004268:DNA-Binding Proteins; D005656:Fungal Proteins; D046911:Macromolecular Substances; D010446:Peptide Fragments; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; D004247:DNA; D011494:Protein Kinases; D003850:Deoxyribonuclease I