{"doi":"10.1101/2021.03.04.433973","title":"Killing of Gram-negative and Gram-positive bacteria by a bifunctional cell wall-targeting T6SS effector","abstract":"Abstract The type VI secretion system (T6SS) is a powerful tool deployed by Gram-negative bacteria to antagonize neighboring organisms. Here, we report that Acinetobacter baumannii ATCC 17978 (Ab17978) secretes D-lysine (D-Lys), increasing the extracellular pH and enhancing the peptidoglycanase activity of the T6SS effector Tse4. This synergistic effect of D-Lys on Tse4 activity enables Ab17978 to outcompete Gram-negative bacterial competitors, demonstrating that bacteria can modify their microenvironment to increase their fitness during bacterial warfare. Remarkably, this lethal combination also results in T6SS-mediated killing of Gram-positive bacteria. Further characterization revealed that Tse4 is a bifunctional enzyme consisting of both lytic transglycosylase and endopeptidase activities, thus representing a novel family of modularly organized T6SS PG degrading effectors with an unprecedented impact in antagonistic bacterial interactions. One sentence summary By modulating local environmental pH through D-Lys secretion, Acinetobacter baumannii enhances the activity of a bifunctional cell wall-targeting T6SS effector, increasing its killing activity against Gram-negative and -positive competitors.","journal":"bioRxiv (Cold Spring Harbor Laboratory)","year":2021,"id":214327,"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":10,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.957,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2021-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":710089,"name":"Víctor Pinedo","orcid":"0000-0002-9727-5224","position":1,"is_corresponding":false},{"id":316670,"name":"Juvenal Lopez","orcid":"0000-0002-3433-2412","position":2,"is_corresponding":false},{"id":316673,"name":"Felipe Cava","orcid":"0000-0001-5995-718X","position":3,"is_corresponding":false},{"id":316674,"name":"Mario F. Feldman","orcid":"0000-0003-4497-0976","position":4,"is_corresponding":false},{"id":316666,"name":"Nguyen-Hung Le","orcid":"0000-0001-8659-6949","position":0,"is_corresponding":true}],"reference_count":27,"raw_metadata":null,"created_at":"2026-07-18T23:52:46.604690Z","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":[]}