Evaluation of NAD(+)-dependent DNA ligase of mycobacteria as a potential target for antibiotics

Korycka-Machala, Malgorzata, Rychta, Ewelina, Brzostek, Anna, Sayer, Heather R., Rumijowska-Galewicz, Anna, Bowater, Richard P. ORCID: https://orcid.org/0000-0002-2745-7807 and Dziadek, Jarosław (2007) Evaluation of NAD(+)-dependent DNA ligase of mycobacteria as a potential target for antibiotics. Antimicrobial Agents and Chemotherapy, 51 (8). pp. 2888-2897. ISSN 1098-6596

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Abstract

Mycobacteria contain genes for several DNA ligases, including ligA, which encodes a NAD+-dependent enzyme that has been postulated to be a target for novel antibacterial compounds. Using a homologous recombination system, direct evidence is presented that wild-type ligA cannot be deleted from the chromosome of Mycobacterium smegmatis. Deletions of native ligA in M. smegmatis could be obtained only after the integration of an extra copy of M. smegmatis or Mycobacterium tuberculosis ligA into the attB site of the chromosome, with expression controlled by chemically inducible promoters. The four ATP-dependent DNA ligases encoded by the M. smegmatis chromosome were unable to replace the function of LigA. Interestingly, the LigA protein from M. smegmatis could be substituted with the NAD+-dependent DNA ligase of Escherichia coli or the ATP-dependent ligase of bacteriophage T4. The conditional mutant strains allowed the analysis of the effect of LigA depletion on the growth of M. smegmatis. The protein level of the conditional mutants was estimated by Western blot analysis using antibodies raised against LigA of M. tuberculosis. This revealed that a strong overproduction or depletion of LigA did not affect the growth or survival of mycobacteria under standard laboratory conditions. In conclusion, although NAD+-dependent DNA ligase is essential for mycobacterial viability, only low levels of protein are required for growth. These findings suggest that very efficient inhibition of enzyme activity would be required if NAD+-dependent DNA ligase is to be useful as an antibiotic target in mycobacteria. The strains developed here will provide useful tools for the evaluation of the efficacy of any appropriate compounds in mycobacteria.

Item Type:	Article
Uncontrolled Keywords:	sdg 3 - good health and well-being ,/dk/atira/pure/sustainabledevelopmentgoals/good_health_and_well_being
Faculty \ School:	Faculty of Science > School of Biological Sciences
UEA Research Groups:	Faculty of Science > Research Groups > Molecular Microbiology Faculty of Science > Research Centres > Centre for Molecular and Structural Biochemistry
Depositing User:	EPrints Services
Date Deposited:	01 Oct 2010 13:38
Last Modified:	24 Sep 2024 09:37
URI:	https://ueaeprints.uea.ac.uk/id/eprint/1612
DOI:	10.1128/AAC.00254-07

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