title: A GCN4 variant with a C-terminal basic region binds to DNA with wild-type affinity.
abstract: Basic-region leucine zipper (bZip) proteins contain a bipartite DNA-binding motif consisting of a leucine zipper dimerization domain and a basic region that directly contacts DNA. In all naturally occurring bZip proteins, the basic region is positioned N-terminal to the leucine zipper. We have designed a series of model bZip peptides in which the basic region of the yeast transcriptional activator GCN4 is placed C-terminal to its leucine zipper. DNA-binding studies demonstrate that the optimal reverse GCN4 (rGCN4) peptide is able to bind specifically and with wild-type affinity to DNA despite this unnatural arrangement of the two subdomains. These results suggest that a thermodynamic basis for the observed N-terminal positioning of the basic region relative to the dimerization domain is unlikely.
authors.affiliation: Department of Chemistry, Indiana University, Bloomington, Indiana 47405, USA.
authors.forename: J J
authors.initials: JJ
authors.lastname: Hollenbeck
authors.forename: D G
authors.initials: DG
authors.lastname: Gurnon
authors.forename: G C
authors.initials: GC
authors.lastname: Fazio
authors.forename: J J
authors.initials: JJ
authors.lastname: Carlson
authors.forename: M G
authors.initials: MG
authors.lastname: Oakley
mesh_terms: D000595:Amino Acid Sequence; D050976:Basic-Leucine Zipper Transcription Factors; D017124:Conserved Sequence / Q000235:genetics; D004268:DNA-Binding Proteins / Q000138:chemical synthesis / Q000235:genetics* / Q000378:metabolism*; D019281:Dimerization; D004926:Escherichia coli / Q000235:genetics; D005656:Fungal Proteins / Q000138:chemical synthesis / Q000235:genetics* / Q000378:metabolism*; D051790:G-Box Binding Factors; D016350:Leucine Zippers / Q000235:genetics*; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D010446:Peptide Fragments / Q000138:chemical synthesis / Q000235:genetics / Q000378:metabolism; D011485:Protein Binding / Q000235:genetics; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D011494:Protein Kinases / Q000138:chemical synthesis / Q000235:genetics* / Q000378:metabolism*; D017433:Protein Structure, Secondary / Q000235:genetics; D017434:Protein Structure, Tertiary / Q000235:genetics; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000138:chemical synthesis; D020449:Repetitive Sequences, Amino Acid / Q000235:genetics; D029701:Saccharomyces cerevisiae Proteins; D013816:Thermodynamics; D014157:Transcription Factors / Q000138:chemical synthesis / Q000235:genetics* / Q000378:metabolism*
chemical_list: D050976:Basic-Leucine Zipper Transcription Factors; D004268:DNA-Binding Proteins; D005656:Fungal Proteins; D051790:G-Box Binding Factors; D010446:Peptide Fragments; D020033:Protein Isoforms; D011994:Recombinant Proteins; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; D011494:Protein Kinases