{"doi":"10.1016/j.jbc.2022.102786","title":"Characterization of the Escherichia coli XPD/Rad3 iron-sulfur helicase YoaA in complex with the DNA polymerase III clamp loader subunit chi (χ)","abstract":"Escherichia coli YoaA aids in the resolution of DNA damage that halts DNA synthesis in vivo in conjunction with χ, an accessory subunit of DNA polymerase III. YoaA and χ form a discrete complex separate from the DNA polymerase III holoenzyme, but little is known about how YoaA and χ work together to help the replication fork overcome damage. Although YoaA is predicted to be an iron-sulfur helicase in the XPD/Rad3 helicase family based on sequence analysis, the biochemical activities of YoaA have not been described. Here, we characterize YoaA and show that purified YoaA contains iron. YoaA and χ form a complex that is stable through three chromatographic steps, including gel filtration chromatography. When overexpressed in the absence of χ, YoaA is mostly insoluble. In addition, we show the YoaA-χ complex has DNA-dependent ATPase activity. Our measurement of the YoaA-χ helicase activity illustrates for the first time YoaA-χ translocates on ssDNA in the 5' to 3' direction and requires a 5' single-stranded overhang, or ssDNA gap, for DNA/DNA unwinding. Furthermore, YoaA-χ preferentially unwinds forked duplex DNA that contains both 3' and 5' single-stranded overhangs versus duplex DNA with only a 5' overhang. Finally, we demonstrate YoaA-χ can unwind damaged DNA that contains an abasic site or damage on 3' ends that stall replication extension. These results are the first biochemical evidence demonstrating YoaA is a bona fide iron-sulfur helicase, and we further propose the physiologically relevant form of the helicase is YoaA-χ.","journal":"Journal of Biological Chemistry","year":2022,"id":277315,"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":8,"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":"2022-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":853038,"name":"Yasmin Ali","orcid":"0000-0001-7413-0885","position":1,"is_corresponding":false},{"id":948866,"name":"Leslie A. Morris","orcid":null,"position":2,"is_corresponding":false},{"id":771469,"name":"Vincent A. Sutera","orcid":"0000-0001-7156-5445","position":3,"is_corresponding":false},{"id":423278,"name":"Elizabeth E. Dudenhausen","orcid":null,"position":4,"is_corresponding":false},{"id":948867,"name":"Margaret Hibnick","orcid":null,"position":5,"is_corresponding":false},{"id":572380,"name":"Susan T. Lovett","orcid":"0000-0003-2792-1857","position":6,"is_corresponding":false},{"id":422379,"name":"Linda B. Bloom","orcid":"0000-0002-6075-4387","position":7,"is_corresponding":false},{"id":948400,"name":"Savannah J. Weeks-Pollenz","orcid":"0000-0002-0676-5683","position":0,"is_corresponding":true}],"reference_count":60,"raw_metadata":null,"created_at":"2026-07-19T00:28:34.768552Z","pmid":"36509145","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":[]}