title: Elk-1 protein domains required for direct and SRF-assisted DNA-binding.
abstract: The Ets-related Elk-1 protein can bind to purine-rich DNA target sites in a sequence specific fashion and, in addition, can form a ternary complex with the c-fos serum response element (SRE) and the serum response factor (SRF). We demonstrate that Elk-1 can readily interchange between its different interaction partners. The amino terminal ETS-domain of Elk-1 was shown to be necessary and sufficient for direct DNA-binding activity. For ternary complex formation with the SRE and SRF, both the Elk-1 ETS-domain as well as flanking sequences up to amino acid 169 were required. Removal of sequences between the ETS-domain and amino acids 137-169 did not abolish ternary complex formation. This suggests the Elk-1 region spanning amino acids 137-169 to contain a protein-protein interaction domain. Furthermore, we have shown that a single amino acid exchange introduced into the ETS-domain can drastically alter the direct DNA-binding affinity of Elk-1 without severely affecting SRF-assisted binding to the SRE. Thus, Elk-1 requires different propensities of the ETS-domain to exert its different modes of DNA sequence recognition.
authors.affiliation: Institute for Molecular Biology, Hannover Medical School, Germany.
authors.forename: R
authors.initials: R
authors.lastname: Janknecht
authors.forename: A
authors.initials: A
authors.lastname: Nordheim
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D001665:Binding Sites / Q000235:genetics; D004247:DNA / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D016762:Genes, fos / Q000235:genetics; D006367:HeLa Cells; D006801:Humans; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D011505:Protein-Tyrosine Kinases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D011518:Proto-Oncogene Proteins; D015682:Retroviridae Proteins, Oncogenic / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D026362:Serum Response Factor; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D050807:ets-Domain Protein Elk-1
chemical_list: D004268:DNA-Binding Proteins; C494112:ELK1 protein, human; D009687:Nuclear Proteins; D011518:Proto-Oncogene Proteins; D015682:Retroviridae Proteins, Oncogenic; D026362:Serum Response Factor; D014157:Transcription Factors; D050807:ets-Domain Protein Elk-1; D004247:DNA; D011505:Protein-Tyrosine Kinases