title: Polypeptide sequences involved in the cleavage of DNA by the restriction endonuclease EcoRI.
abstract: We have prepared a variety of fragments of the restriction endonuclease EcoRI by partial or total CNBr or acid cleavage of the protein. These fragments were isolated by preparative polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate. They were analyzed in a qualitative manner for phosphodiesterase activity. Antibodies against these fragments were elicited in rats and tested for binding to native EcoRI in an enzyme-linked immunoassay. We conclude from these experiments that the DNA binding site of EcoRI is located in the COOH-terminal half of the molecule, close to and probably comprising amino acid residues 137 to 157. This conclusion is reinforced by the observation that this sequence shows homology to the sequences of the recognition helix of other gene-regulatory proteins.
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000276:immunology / Q000378:metabolism*; D001665:Binding Sites; D003488:Cyanogen Bromide; D004262:DNA Restriction Enzymes / Q000276:immunology / Q000378:metabolism*; D004279:DNA, Viral / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000378:metabolism; D015246:Deoxyribonuclease EcoRI; D004797:Enzyme-Linked Immunosorbent Assay; D010446:Peptide Fragments / Q000276:immunology / Q000378:metabolism*; D012689:Sequence Homology, Nucleic Acid; D013379:Substrate Specificity
chemical_list: D001426:Bacterial Proteins; D004279:DNA, Viral; D004268:DNA-Binding Proteins; D010446:Peptide Fragments; D004262:DNA Restriction Enzymes; D015246:Deoxyribonuclease EcoRI; D003488:Cyanogen Bromide