The actinobacterium Tsukamurella paurometabola has a functionally divergent arylamine N-acetyltransferase (NAT) homolog

PtmC Catalyzes the Final Step of Thioplatensimycin, Thioplatencin, and Thioplatensilin Biosynthesis and Expands the Scope of Arylamine N-Acetyltransferases

“…While members of the NAT family are known for their arylamine substrate promiscuity, they are highly specific for their acyl-CoA substrate, typically acetyl-CoA, with only rare instances of alternative CoA- or pantetheine-linked substrates. − As PtmC apparently utilizes all three ketolide-CoAs 16 – 18 efficiently (Figure ), the kinetic parameters of PtmC for 16 – 18 were determined, with carboxylic acid 8 at 750 mM and varying concentrations of 16 , 17 , or 18 (from 5 to 120 μM; SI Materials and Methods). PtmC-catalyzed formation of 1 – 3 followed Michaelis–Menten kinetics, with K m values of 24.0 ± 7.0 mM (for 16 ), 6.3 ± 1.3 mM (for 17 ), and 9.9 ± 3.8 mM (for 18 ), and k cat values of 73.4 ± 8.1 min –1 (for 16 ), 38.5 ± 2.1 min –1 (for 17 ), and 46.8 ± 6.2 min –1 (for 18 ), respectively (Figure S72B).…”

“…The NAT family typically catalyzes the N- and O-acetylation of arylamines, arylhydrazines, arylhydroxylamines, and related metabolites (Figure S2). , These enzymes have been well studied for their role in xenobiotic detoxification in bacterial pathogens, especially regarding metabolism of the antituberculosis drug isoniazid, and in humans, including as a cancer target. , While NATs often have some promiscuity toward their arylamine substrates, they are highly specific for the acetyl donor, i.e., acetyl-CoA, with only rare exceptions. − Thus, all NATs share a well-conserved structural fold that enables the transient formation of an acetyl-thioester species at the catalytic cysteine residue before transferring the acetyl group to the arylamine substrates (Figure S3). ,, To date, no NAT has been characterized from natural product biosynthetic pathways.…”

A taxonomically representative strain collection to explore xenobiotic and secondary metabolism in bacteria

“…We have become interested in T . paurometabola DSM 20162 T during our earlier studies of microbial 3,4-DCA detoxification through enzymatic conjugation reactions catalyzed by arylamine N- acetyltransferases (NATs) [ 37 , 38 ], as this actinobacterium was found to possess a NAT homolog with unusual properties [ 37 ]. Here, T .…”

“…paurometabola DSM 20162 T was challenged with a concentration range of 3,4-DCA added to the culture medium, which was then subjected to extraction and LC-MS analysis of its organic content for possible N- acetylated, N- propionylated and/or N- malonylated metabolic derivatives. The corresponding authentic compounds had been synthesized previously [ 37 ] and were available in-house as standards. Analysis of the medium-only control was used to facilitate the identification of fragments unique to the xenobiotic-amended cultures, particularly those fragments specific to the postulated N- acylated derivatives of 3,4-DCA.…”

“…While T . paurometabola DSM 20162 T appeared sensitive to BOA and 2AP, it has demonstrated robustness towards 3,4-DCA, a man-made pesticide residue abundant in farmlands [ 37 ]. Elimination of aromatic amines, particularly chloroanilines like 3,4-DCA, has been very challenging, as those compounds can be toxic and resistant to microbial biodegradation [ 60 , 61 ].…”