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Precipitant–ligand exchange technique reveals the ADP binding mode in Mycobacterium tuberculosis dethiobiotin synthetase
Author(s) -
Thompson Andrew P.,
Wegener Kate L.,
Booker Grant W.,
Polyak Steven W.,
Bruning John B.
Publication year - 2018
Publication title -
acta crystallographica section d
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.374
H-Index - 138
ISSN - 2059-7983
DOI - 10.1107/s2059798318010136
Subject(s) - ligand (biochemistry) , chemistry , mycobacterium tuberculosis , ligand efficiency , enzyme , stereochemistry , biochemistry , combinatorial chemistry , tuberculosis , receptor , medicine , pathology
Dethiobiotin synthetase from Mycobacterium tuberculosis ( Mt DTBS) is a promising antituberculosis drug target. Small‐molecule inhibitors that target Mt DTBS provide a route towards new therapeutics for the treatment of antibiotic‐resistant tuberculosis. Adenosine diphosphate (ADP) is an inhibitor of Mt DTBS; however, structural studies into its mechanism of inhibition have been unsuccessful owing to competitive binding to the enzyme by crystallographic precipitants such as citrate and sulfate. Here, a crystallographic technique termed precipitant–ligand exchange has been developed to exchange protein‐bound precipitants with ligands of interest. Proof of concept for the exchange method was demonstrated using cytidine triphosphate (CTP), which adopted the same binding mechanism as that obtained with traditional crystal‐soaking techniques. Precipitant–ligand exchange also yielded the previously intractable structure of Mt DTBS in complex with ADP solved to 2.4 Å resolution. This result demonstrates the utility of precipitant–ligand exchange, which may be widely applicable to protein crystallography.