{"doi":"10.1073/pnas.93.24.13583","title":"A small engineered protein lacks structural uniqueness by increasing the side-chain conformational entropy","abstract":"<jats:p>\n                    A small globular protein, the third repeat of the c-Myb DNA-binding\n domain, which is composed of 54 amino acid residues, was engineered so\n as to understand the structural uniqueness of native proteins. This\n small protein has three α-helices that form a helix-turn-helix\n structure, which is maintained by the hydrophobic core with three Ile\n residues. One of the mutant proteins, with two of the buried Ile\n (Ile-155 and Ile-181) substituted with Leu residues, showed multiple\n conformations, as monitored by heteronuclear magnetic resonance\n spectroscopy for\n                    <jats:sup>13</jats:sup>\n                    C- and\n                    <jats:sup>15</jats:sup>\n                    N-labeled proteins.\n The increase in the side-chain conformational entropy, caused by\n changing the Ile to a Leu residue on an α-helix, could engender the\n lack of structural uniqueness. In native proteins, the conformations of\n not only the β-branched side chains, but also those of the\n neighboring bulky side chains, can be greatly restricted, depending\n upon the local backbone structure.\n                  </jats:p>","journal":"Proceedings of the National Academy of Sciences","year":1996,"id":632451,"datarank":0.4636563680037475,"base_score":3.091042453358316,"endowment":3.091042453358316,"self_citation_contribution":0.4636563680037475,"citation_network_contribution":0.0,"self_endowment_contribution":0.4636563680037475,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":21,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":null,"is_data_producer":false,"deposit_databanks":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":546096,"name":"Masayuki Oda","orcid":"0000-0002-8568-4223","position":1,"is_corresponding":false},{"id":86694,"name":"Haruki Nakamura","orcid":"0000-0001-6690-5863","position":2,"is_corresponding":false},{"id":1639397,"name":"Koji Furukawa","orcid":null,"position":0,"is_corresponding":false}],"reference_count":0,"raw_metadata":{"has_enrichment":true,"resolved":true,"title":"A small engineered protein lacks structural uniqueness by increasing the side-chain conformational entropy","abstract":"<jats:p>\n                    A small globular protein, the third repeat of the c-Myb DNA-binding\n domain, which is composed of 54 amino acid residues, was engineered so\n as to understand the structural uniqueness of native proteins. This\n small protein has three α-helices that form a helix-turn-helix\n structure, which is maintained by the hydrophobic core with three Ile\n residues. One of the mutant proteins, with two of the buried Ile\n (Ile-155 and Ile-181) substituted with Leu residues, showed multiple\n conformations, as monitored by heteronuclear magnetic resonance\n spectroscopy for\n                    <jats:sup>13</jats:sup>\n                    C- and\n                    <jats:sup>15</jats:sup>\n                    N-labeled proteins.\n The increase in the side-chain conformational entropy, caused by\n changing the Ile to a Leu residue on an α-helix, could engender the\n lack of structural uniqueness. In native proteins, the conformations of\n not only the β-branched side chains, but also those of the\n neighboring bulky side chains, can be greatly restricted, depending\n upon the local backbone structure.\n                  </jats:p>","is_dataset_classified":null,"base_score":3.091042453358316,"endowment":3.091042453358316,"datacite_reuse_total":0,"file_count":0,"downloads":0,"views":0,"has_version_chain":false,"is_dataset":false,"is_oa":false,"pmid":"8942977","pmcid":"PMC19356","openalex_id":"https://openalex.org/W2031982772","authors":[],"funders":[],"total_grants":0,"fwci":0.4098,"citation_percentile":0.59564094,"influential_citations":0,"citation_trend":[{"year":2013,"count":1},{"year":2015,"count":1},{"year":2020,"count":2},{"year":2021,"count":1},{"year":2022,"count":2},{"year":2025,"count":2}],"oa_status":"green","license":null,"oa_locations":[{"url":"https://www.ncbi.nlm.nih.gov/pmc/articles/19356","host_type":"repository"},{"url":"https://www.ncbi.nlm.nih.gov/pmc/articles/19356","host_type":"repository"},{"url":"https://pnas.org/doi/pdf/10.1073/pnas.93.24.13583","host_type":"publisher"},{"url":"https://doi.org/10.1073/pnas.93.24.13583","host_type":"journal"},{"url":"https://pubmed.ncbi.nlm.nih.gov/8942977","host_type":"repository"},{"url":"http://europepmc.org/pmc/articles/PMC19356","host_type":"repository"}],"fields_of_study":["Protein Structure and Dynamics","Enzyme Structure and Function","RNA and protein synthesis mechanisms"],"mesh_terms":["Amino Acid Sequence","Circular Dichroism","DNA-Binding Proteins","Isoleucine","Leucine","Models, Molecular","Molecular Sequence Data","Magnetic Resonance Spectroscopy","Protein Conformation","Proto-Oncogene Proteins","Recombinant Proteins","Trans-Activators","Mutagenesis, Site-Directed","Point Mutation","Protein Structure, Secondary","Protein Structure, Tertiary","Helix-Turn-Helix Motifs","Entropy","Proto-Oncogene Proteins c-myb"],"keywords":["Side chain","Conformational entropy","Heteronuclear molecule","Protein structure","Chemistry","Helix (gastropod)","Globular protein","Nuclear magnetic resonance spectroscopy","Stereochemistry","Crystallography","Biophysics","Biochemistry","Biology","Molecule"],"sdg_mappings":[{"sdg_number":0,"sdg_label":"Life in Land"}],"linked_datasets":[],"clinical_trials":[],"software_tools":[],"database_accessions":[{"name":"pdb"}],"source":"live","citation_network_status":"fetched"},"created_at":"2026-08-06T09:47:42.357670Z","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":[]}