{"doi":"10.17615/4x3t-m517","title":"Suppression of a signal sequence mutation by an amino acid substitution in the mature portion of the maltose-binding protein.","abstract":"An unusual spontaneous pseudorevertant of an Escherichia coli strain carrying the signal sequence point mutation malE14-1 was characterized. The suppressor mutation, malE2261, resulted in a single substitution of an aspartyl residue for a tyrosyl residue at position 283 in the sequence of the mature maltose-binding protein. The precursor retained the malE14-1 point mutation in the signal sequence. The pseudorevertant carrying both malE14-1 and malE2261 exported twice the amount of maltose-binding protein as that of the mutant carrying the malE14-1 allele alone but only 18% of the amount exported by a strain producing wild-type maltose-binding protein. A strain carrying the suppressor allele malE2261 in combination with a wild-type signal sequence exported normal quantities of maltose-binding protein to the periplasm. Mature MalE2261 had a Kd for maltose of 27 microM, compared with 3.6 microM for mature wild-type maltose-binding protein. The precursor species than contained both changes resulting from malE14-1 and malE2261 was significantly less stable in the cytoplasm than was the precursor containing only the change encoded by malE14-1.","journal":"UNC Libraries","year":2020,"id":138084,"datarank":0.0,"base_score":0.0,"endowment":0.0,"self_citation_contribution":0.0,"citation_network_contribution":0.0,"self_endowment_contribution":0.0,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":0,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9401,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2020-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":599552,"name":"L L Randall","orcid":null,"position":1,"is_corresponding":false},{"id":599553,"name":"K A Walsh","orcid":null,"position":2,"is_corresponding":false},{"id":599554,"name":"P J Bassford","orcid":null,"position":3,"is_corresponding":false},{"id":599555,"name":"J Bollinger","orcid":null,"position":4,"is_corresponding":false},{"id":599556,"name":"W H Cover","orcid":null,"position":5,"is_corresponding":false},{"id":599551,"name":"J P Ryan","orcid":null,"position":0,"is_corresponding":true}],"reference_count":0,"raw_metadata":null,"created_at":"2026-07-18T23:16:59.449905Z","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":[]}