Molecular characterization of the GCN4-DNA complex.
AUTOR(ES)
Gartenberg, M R
RESUMO
We report studies of the DNA complex formed by GCN4, a transcriptional activator of eukaryotic amino acid biosynthetic operons. The DNA thermodynamic binding domain, defined by primer extension analysis, spans at least 18 base pairs, a site much larger than the 9-base-pair consensus defined by homology with naturally occurring binding sites. Chemical modification experiments reveal multiple sites of protein-DNA contact: methylation of any guanine N-7 or adenine N-3, ethylation of any phosphate oxygen, or elimination of any nucleoside within a region spanning nearly one and a half turns of the double helix reduces the binding affinity of the complex measurably. Nevertheless, the protein yields no detectable hydroxyl radical footprint, implying that the minor groove is reagent-accessible in the protein-DNA complex. These chemical modification patterns indicate that GCN4 does not utilize any of the DNA-recognition motifs of paradigm DNA-binding proteins. Assays to detect DNA bending induced by truncated or intact GCN4 indicate that protein conformation and not a protein-induced bend is responsible for the anomalous electrophoretic behavior of GCN4-DNA complexes.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=54466Documentos Relacionados
- Uracil interference, a rapid and general method for defining protein-DNA interactions involving the 5-methyl group of thymines: the GCN4-DNA complex.
- Characterization of the ATF/CREB site and its complex with GCN4
- Characterization of the histone core complex.
- An EMSA-based method for determining the molecular weight of a protein--DNA complex.
- Molecular mapping within the mouse albino-deletion complex.