Armeniaspirols inhibit the AAA+ proteases ClpXP and ClpYQ leading to cell division arrest in Gram-positive bacteria

Resistance-Guided Mining of Bacterial Genotoxins Defines a Family of DNA Glycosylases

“…Asukamycin contains a modified PKS scaffold and an electrophilic epoxide ring and has been shown to act as both a farsenyltransferase inhibitor and a molecular glue between the UBR7 E3 ubiquitin ligase and the TP53 tumor suppressor, leading to cell death ( 44 , 45 ). Armeniaspirol contains a unique chlorinated pyrrole and inhibits the AAA+ proteases ClpXP and ClpYQ, leading to cell division arrest in Gram-positive bacteria ( 46 ). The other two BGCs produce compounds of known structure but unknown function.…”

Total synthesis and mechanism of action of the antibiotic armeniaspirol A

“…In a recently published study, Labana et al (2021) observed that the treatment of Bacillus subtilis with 4 does not induce a proteomic signature that matches common antibiotics mechanisms like inhibition of protein synthesis, fatty acid biosynthesis, cell wall biosynthesis, or DNA damaging. 9 Furthermore, the authors applied a chemoproteomic approach to discover several binding partners of a covalent capture probe derived from 4, and they report that 4 inhibited the protease and ATPase activities of ClpYQ and ClpXP complexes with IC 50 values between 15 and 42 μM, and ATP hydrolysis was impaired at IC 50 values between 42 and 108 μM. These enzymes are components of the bacterial divisome, and Labana et al also show microscopic images of an abnormal distribution of these proteins within the cells upon incubation with 4, combined with dysfunctional cell division and deduce that the bacterial divisome is impaired.…”

“…In a recently published study, Labana et al (2021) observed that the treatment of Bacillus subtilis with 4 does not induce a proteomic signature that matches common antibiotics mechanisms like inhibition of protein synthesis, fatty acid biosynthesis, cell wall biosynthesis, or DNA damaging. 9 Furthermore, the authors applied a chemoproteomic approach to discover several binding partners of a covalent capture probe derived from 4, and they report that 4 inhibited the protease and ATPase activities of and 33%, respectively, at a concentration of 100 µM (Supplementary Figure S7). In line with the Labana study, a covalent modification of ClpP by 2 was not observed (Supplementary Figure S8).…”

“…Intriguingly, while we drafted this manuscript, Labana et al published the interaction of the 3 armeniaspirol derivative 4 with the proteases ClpXP and ClpYQ -a mechanism that is different to the ones we report below (see discussion). 9 In a first synthesis of armeniaspirols, 10 we have constructed the spiro- [4.4]non-8-ene scaffold through an attack of the phenolic group at C-8 of the benzoylated pyrrole ring, mimicking the presumed and later confirmed biosynthesis of the natural product 11,12 (Supplementary Scheme S1). The synthesis was short (7 steps, 13.8% overall yield), but the oxidative chlorination conditions led to chloroarmeniaspirol 4 rather than the natural product itself, as the chlorination at the pyrrole ring was inevitably associated with an undesired chlorination at the electron-rich C2 position.…”

“…Intriguingly, while we drafted this manuscript, Labana et al published the interaction of the armeniaspirol derivative 4 with the proteases ClpXP and ClpYQ – a mechanism that is different to the ones we report below (see discussion). 9 …”