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Identification of the target and mode of action for the prokaryotic nucleotide excision repair inhibitor ATBC

Bernacchia, Lorenzo, Paris, Antoine, Gupta, Arya, Moores, Alexandra A., Kad, Neil M. (2022) Identification of the target and mode of action for the prokaryotic nucleotide excision repair inhibitor ATBC. Bioscience Reports, 42 (6). Article Number BSR2022040. ISSN 0144-8463. E-ISSN 1573-4935. (doi:10.1042/BSR20220403) (KAR id:95696)

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In bacteria, nucleotide excision repair (NER) plays a major role in repairing DNA damage from a wide variety of sources. Therefore, its inhibition offers potential to develop a new antibacterial in combination with adjuvants, such as UV light. To date, only one known chemical inhibitor of NER is 2-(5-amino-1,3,4-thiadiazol-2-yl)benzo(f)chromen-3-one (ATBC) exists and targets Mycobacterium tuberculosis NER. To enable the design of future drugs, we need to understand its mechanism of action. To determine the mechanism of action, we used in silico structure-based prediction, which identified the ATP-binding pocket of Escherichia coli UvrA as a probable target. Growth studies in E. coli showed it was nontoxic alone, but able to impair growth when combined with DNA-damaging agents, and as we predicted, it reduced by an approximately 70% UvrA's ATPase rate. Since UvrA's ATPase activity is necessary for effective DNA binding, we used single-molecule microscopy to directly observe DNA association. We measured an approximately sevenfold reduction in UvrA molecules binding to a single molecule of dsDNA suspended between optically trapped beads. These data provide a clear mechanism of action for ATBC, and show that targeting UvrA's ATPase pocket is effective and ATBC provides an excellent framework for the derivation of more soluble inhibitors that can be tested for activity.

Item Type: Article
DOI/Identification number: 10.1042/BSR20220403
Uncontrolled keywords: DNA synthesis and repair, inhibitor, multidrug resistance
Subjects: Q Science
Divisions: Divisions > Division of Natural Sciences > Biosciences
Depositing User: Neil Kad
Date Deposited: 07 Jul 2022 10:02 UTC
Last Modified: 08 Jul 2022 08:33 UTC
Resource URI: (The current URI for this page, for reference purposes)
Kad, Neil M.:
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