Solution structure of the basic region from the transcriptional activator GCN4.
The structure of the basic region (i.e., the region responsible for sequence-specific binding to DNA) of the transcriptional activator GCN4 was studied. Two peptide fragments containing either the basic region alone (residues 240-280) or the basic and the dimerization leucine zipper domains (220-280) were synthesized and investigated by nuclear magnetic resonance and circular dichroic spectroscopy. The basic region in the absence of DNA appears as a mobile flexible segment folded into a loose helix. The helical stability increases upon addition of trifluoroethanol and/or lowering of the temperature. Dimerization via the leucine zipper does not affect the three-dimensional structure of the basic region. Possible consequences for the binding to DNA are discussed.
Saudek
V
V
Merrell Dow Research Institute, Strasbourg, France.
Pasley
H S
HS
Gibson
T
T
Gausepohl
H
H
Frank
R
R
Pastore
A
A
D000595:Amino Acid Sequence; D002942:Circular Dichroism; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000648:ultrastructure*; D005656:Fungal Proteins / Q000737:chemistry / Q000648:ultrastructure*; D006860:Hydrogen Bonding; D007526:Isoelectric Point; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D010455:Peptides / Q000138:chemical synthesis / Q000737:chemistry; D011487:Protein Conformation; D011494:Protein Kinases; D029701:Saccharomyces cerevisiae Proteins; D012996:Solutions; D014157:Transcription Factors / Q000737:chemistry / Q000648:ultrastructure*
D004268:DNA-Binding Proteins; D005656:Fungal Proteins; D010455:Peptides; D029701:Saccharomyces cerevisiae Proteins; D012996:Solutions; D014157:Transcription Factors; D011494:Protein Kinases