title: A peptide motif that recognizes A.T tracts in DNA.
abstract: The DAT1 gene of Saccharomyces cerevisiae encodes a DNA binding protein that specifically interacts with nonalternating oligo(A).oligo(T) tracts (A.T tracts). Deletion analysis of DAT1 coding information showed that the amino-terminal 36 residues are sufficient for specific DNA binding activity. Furthermore, a 35-residue synthetic peptide corresponding to amino acids 2-36 bound to A.T tracts with an equilibrium dissociation constant of 4 x 10(-10) M. Within this region the pentad Gly-Arg-Lys-Pro-Gly is repeated three times. Mutational analysis revealed that the Arg side chains are required for high-affinity binding, whereas the other pentad side chains are dispensable. Chemical interference experiments showed that the DAT1 protein interacts with the minor groove of the double helix. The data suggest that the pentad arginines interact in a cooperative manner with a repeated minor groove feature of A.T tract DNA to achieve high-affinity recognition. Amino acid similarities with other DNA binding proteins suggest that the DAT1 protein pentad represents a specialized example of a widespread motif used by proteins to recognize A.T base pairs.
authors.affiliation: Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, PA 19107.
authors.forename: B J
authors.initials: BJ
authors.lastname: Reardon
authors.forename: R S
authors.initials: RS
authors.lastname: Winters
authors.forename: D
authors.initials: D
authors.lastname: Gordon
authors.forename: E
authors.initials: E
authors.lastname: Winter
mesh_terms: D000595:Amino Acid Sequence; D001120:Arginine / Q000737:chemistry; D001483:Base Sequence; D001665:Binding Sites; D004268:DNA-Binding Proteins / Q000737:chemistry* / Q000378:metabolism; D050483:Dopamine Plasma Membrane Transport Proteins; D005656:Fungal Proteins / Q000737:chemistry / Q000378:metabolism; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins; D009838:Oligodeoxyribonucleotides / Q000737:chemistry; D010446:Peptide Fragments / Q000737:chemistry / Q000378:metabolism; D011067:Poly dA-dT / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins; D013329:Structure-Activity Relationship
chemical_list: C060858:DAT1 protein, S cerevisiae; D004268:DNA-Binding Proteins; D050483:Dopamine Plasma Membrane Transport Proteins; D005656:Fungal Proteins; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins; D009419:Nerve Tissue Proteins; D009838:Oligodeoxyribonucleotides; D010446:Peptide Fragments; D029701:Saccharomyces cerevisiae Proteins; D011067:Poly dA-dT; D001120:Arginine