{"doi":"10.1101/2021.07.01.450732","title":"High-density transposon mutagenesis in <i>Mycobacterium abscessus</i> identifies an essential penicillin-binding lipo-protein (PBP-lipo) involved in septal peptidoglycan synthesis and antibiotic sensitivity","abstract":"Abstract Mycobacterium abscessus ( Mab ) is a rapidly growing non-tuberculous mycobacterium (NTM) that causes a wide range of infections. Treatment of Mab infections is difficult because the bacterium is intrinsically resistant to many classes of antibiotics. Developing new and effective treatments against Mab requires a better understanding of the unique vulnerabilities that can be targeted for future drug development. To achieve this, we identified essential genes in Mab by conducting transposon-sequencing (TnSeq) on the reference Mab strain ATCC 19977. We generated ∼51,000 unique transposon mutants and used this high-density library to identify 362 essential genes for in vitro growth. To investigate species-specific vulnerabilities in Mab , we further characterized MAB_3167c , a predicted penicillin-binding-lipoprotein (PBP-lipo) that is essential in Mab and non-essential in Mycobacterium tuberculosis ( Mtb ). We found that PBP-lipo primarily localizes to the subpolar region and later to the septum as cells prepare to divide. Depletion of Mab PBP-lipo causes cells to elongate, develop ectopic branches, and form multiple septa. Knockdown of PBP-lipo along with PbpB, DacB1, and a carboxypeptidase, MAB_0519 lead to synergistic growth arrest. In contrast, these genetic interactions were absent in the Mtb model organism, Mycobacterium smegmatis , indicating that the PBP-lipo homologs in the two species exist in distinct genetic networks. Finally, repressing PBP-lipo sensitized the reference strain and 11 Mab clinical isolates to several classes of antibiotics, including the β-lactams, ampicillin and amoxicillin by greater than 128-fold. Altogether, this study presents PBP-lipo as a key enzyme to study Mab specific processes in cell wall synthesis and importantly positions PBP-lipo as an attractive drug target to treat Mab infections.","journal":"bioRxiv (Cold Spring Harbor Laboratory)","year":2021,"id":216657,"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":4,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9571,"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":812573,"name":"Bouchra S. Benghomari","orcid":"0000-0002-2947-140X","position":1,"is_corresponding":false},{"id":270336,"name":"Junhao Zhu","orcid":"0000-0002-3301-5677","position":2,"is_corresponding":false},{"id":678865,"name":"Ian D. Wolf","orcid":"0000-0002-2455-6148","position":3,"is_corresponding":false},{"id":812964,"name":"Shreya Singhvi","orcid":null,"position":4,"is_corresponding":false},{"id":555891,"name":"Charles L. Dulberger","orcid":"0000-0002-1334-5468","position":5,"is_corresponding":false},{"id":281182,"name":"Thomas R. Ioerger","orcid":"0000-0001-8702-9102","position":6,"is_corresponding":false},{"id":247777,"name":"Eric J. Rubin","orcid":"0000-0001-5120-962X","position":7,"is_corresponding":false},{"id":440221,"name":"Chidiebere Akusobi","orcid":"0000-0002-1611-0015","position":0,"is_corresponding":true}],"reference_count":58,"raw_metadata":null,"created_at":"2026-07-18T23:53:11.245932Z","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":[]}