Type IV traffic ATPase TrwD as molecular target to inhibit bacterial conjugation

Abstract

Summary Bacterial conjugation is the main mechanism responsible for the dissemination of antibiotic resistance genes. Hence, the search for specific conjugation inhibitors is paramount in the fight against the spread of these genes. In this pursuit, unsaturated fatty acids have been found to specifically inhibit bacterial conjugation. Despite the growing interest on these compounds, their mode of action and their specific target remain unknown. Here, we identified TrwD, a Type IV secretion traffic ATPase, as the molecular target for fatty acid-mediated inhibition of conjugation. Moreover, 2-alkynoic fatty acids, which are also potent inhibitors of bacterial conjugation, are also powerful inhibitors of the ATPase activity of TrwD. Characterization of the kinetic parameters of ATPase inhibition has led us to identify the catalytic mechanism by which fatty acids exert their activity. These results open a new avenue for the rational design of inhibitors of bacterial conjugation in the fight against the dissemination of antibiotic resistance genes.

X‐ray crystal structures of the type IVb secretion system DotB ATPases

“…Therefore, our study reveals an unprecedented level of conformational complexity, which might be exploited functionally at many different levels. Such a large conformational spectrum might be the reason why it has been difficult to design VirB11‐targetting drugs . The novel insights we now provide might prove decisive in progressing these efforts to a successful conclusion.…”

Inhibiting conjugation as a tool in the fight against antibiotic resistance

“…Experiments have also identified unsaturated and 2‐alkynoic fatty acids as inhibitors of conjugation. These target the ATPase associated with the T4SS (Ripoll‐Rozada et al, ). Tanzawaic acids show particular promise having relatively broad host‐range against different types of plasmid conjugation while being relatively nontoxic (to bacteria, fungi, and human cells; Getino et al, ).…”

Antibacterial Activity of Hexadecynoic Acid Isomers toward Clinical Isolates of Multidrug‐Resistant Staphylococcus aureus

“…This "cleaved complex" is characterized by the presence of DNA breaks, which have been crystallized and found to have the fluoroquinolone C-7 ring system facing the GyrB subunit (Mustaev et al, 2014). In the case of 1, it was demonstrated that this compound displayed COIN activity in E. coli by the inhibition of TrwD ATPase (Garcia-Cazorla et al, 2018;Getino et al, 2015;Ripoll-Rozada et al, 2016). It was shown that 1 binds to the N-terminal domain (NTD) and the linker region of TrwD ATPase resulting in the restriction of the movement of the NTD over the catalytic domain (CTD), which would result in a reduction of the TrwD ATPase activity (Ripoll-Rozada et al, 2016).…”

“…In the case of 1, it was demonstrated that this compound displayed COIN activity in E. coli by the inhibition of TrwD ATPase (Garcia-Cazorla et al, 2018;Getino et al, 2015;Ripoll-Rozada et al, 2016). It was shown that 1 binds to the N-terminal domain (NTD) and the linker region of TrwD ATPase resulting in the restriction of the movement of the NTD over the catalytic domain (CTD), which would result in a reduction of the TrwD ATPase activity (Ripoll-Rozada et al, 2016). These findings are revealing because S. aureus DNA gyrase contains a GyrB subunit, an enzymatic region that has ATPase activity (Eakin et al, 2012;Fàbrega et al, 2009), which could explain the observed inhibitory activity of 1 toward the S. aureus DNA gyrase.…”

“…In a study performed by Ripoll‐Rozada and collaborators, they identified that TrwD, a Type IV secretion traffic ATPase, is involved in the 1 ‐mediated conjugation inhibition. Moreover, 1 , which is also a potent COIN, displayed powerful inhibitory ATPase activity of TrwD as well, demonstrating that TrwD is the molecular target of 1 (Garcia‐Cazorla et al, ; Ripoll‐Rozada et al, ).…”