{"doi":"10.1111/j.1432-1033.1977.tb11819.x","title":"Construction, Isolation and Implications of Repressor‐galactosidase ·ß‐galactosidase Hybrid Molecules","abstract":"<jats:p> <jats:italic>Escherichia coli</jats:italic> heterogenotes, which produce hybrid molecules between the chimaeric protein repressor‐galactosidase and the enzyme β‐galactosidase, were constructed. Repressor‐galactosidase. in which fully active <jats:italic>lac</jats:italic> repressor is covalently linked to active β‐galactosidase, is an aggregate with a core structure of four β‐galactosidase parts and two peripheral <jats:italic>lac</jats:italic> repressor dimers. The <jats:italic>lac</jats:italic> repressor dimers, which are separated by tetrameric β‐galactosidase, retain all the biological activities of tetra‐meric <jats:italic>lac</jats:italic> repressor. Substitution of repressor‐galactosidase subunits with β‐galactosidase subunits leads to hybrid molecules with <jats:italic>y</jats:italic>β‐galactosidase subunits aggregated with (4‐<jats:italic>y</jats:italic>) repressor‐galactosi‐dase subunits (where <jats:italic>y</jats:italic>= 1, 2 or 3). A 2:2 hybrid, <jats:italic>i.e.</jats:italic> a tetrameric β‐galactosidase core with one <jats:italic>lac</jats:italic> repressor dimer grafted to it, binds at least 100 times less strongly to <jats:sup>32</jats:sup>P‐labelled λp<jats:italic>lac</jats:italic> DNA than pure <jats:italic>lac</jats:italic> repressor or repressor‐galactosidase.</jats:p><jats:p>The data suggest a model in which <jats:italic>lac</jats:italic> repressor binds with two subunits to <jats:italic>lac</jats:italic> operator and with the other two subunits elsewhere on the DNA, possibly on sequences like the <jats:italic>lac</jats:italic> operator.</jats:p>","journal":"European Journal of Biochemistry","year":1977,"id":17729,"datarank":3.7757812590359445,"base_score":4.127134385045092,"endowment":4.127134385045092,"self_citation_contribution":0.6190701577567639,"citation_network_contribution":3.1567111012791806,"self_endowment_contribution":0.6190701577567639,"citer_contribution":3.1567111012791806,"corpus_percentile":null,"corpus_rank":null,"citation_count":61,"citer_count":47,"citers_with_citation_signal":45,"citers_with_endowment":45,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":null,"is_oa":false,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":null,"fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":125815,"name":"Benno MÜLLER‐HILL","orcid":null,"position":1,"is_corresponding":false},{"id":125814,"name":"Jürgen KANIA","orcid":null,"position":0,"is_corresponding":false}],"reference_count":0,"raw_metadata":{"has_enrichment":true,"base_score":4.127134385045092,"endowment":4.127134385045092,"datacite_reuse_total":0,"file_count":0,"downloads":0,"views":0,"has_version_chain":false,"is_dataset":false,"is_oa":false,"pmid":"411650","pmcid":null,"openalex_id":"https://openalex.org/W2026607812","authors":[],"funders":[],"total_grants":0,"fwci":3.5904,"citation_percentile":0.92539285,"influential_citations":0,"citation_trend":[{"year":2012,"count":1},{"year":2013,"count":1},{"year":2014,"count":1},{"year":2015,"count":1},{"year":2018,"count":1}],"oa_status":"closed","license":"http://onlinelibrary.wiley.com/termsAndConditions#vor","oa_locations":[{"url":"https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1432-1033.1977.tb11819.x","host_type":"publisher"},{"url":"https://febs.onlinelibrary.wiley.com/doi/pdf/10.1111/j.1432-1033.1977.tb11819.x","host_type":"publisher"},{"url":"https://doi.org/10.1111/j.1432-1033.1977.tb11819.x","host_type":"journal"},{"url":"https://pubmed.ncbi.nlm.nih.gov/411650","host_type":"repository"}],"fields_of_study":["Enzyme Structure and Function","Animal Genetics and Reproduction","Amino Acid Enzymes and Metabolism","Biology","Medicine","Bacterial Proteins","DNA, Bacterial","Enzyme Repression","Escherichia coli","Galactosidases","Lactose","Protein Binding","Protein Conformation","Protein Multimerization","Structure-Activity Relationship","beta-Galactosidase"],"mesh_terms":["Bacterial Proteins","beta-Galactosidase","DNA, Bacterial","Enzyme Repression","Escherichia coli","Galactosidases","Lactose","Protein Binding","Protein Conformation","Structure-Activity Relationship","Protein Multimerization"],"keywords":["Isolation (microbiology)","Beta-galactosidase","Repressor","Chemistry","Biology","Gene","Biochemistry","Microbiology","Gene expression"],"sdg_mappings":[{"sdg_number":0,"sdg_label":"Life below water"}],"linked_datasets":[],"clinical_trials":[],"software_tools":[],"database_accessions":[],"source":"live","citation_network_status":"fetched"},"created_at":"2026-06-02T20:38:43.287737Z","pmid":null,"pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}