Characterization of the ModABC Molybdate Transport System of Pseudomonas putida in Nicotine Degradation

Abstract

Pseudomonas putida J5 is an efficient nicotine-degrading bacterial strain that catabolizes nicotine through the pyrrolidine pathway. In our previous study, we used Tn5 transposon mutagenesis to investigate nicotine metabolism-associated genes, and 18 nicotine degradation-deficient mutants were isolated from 16,324 Tn5-transformants. Three of the mutants were Tn5 inserts into the modABC gene cluster that encoded an ABC-type, high-affinity, molybdate transporter. In-frame deletion of the modABC genes abolished the nicotine-degrading ability of strain J5, and complementation with modABC either from P. putida or Arthrobacter oxidans restored the degrading activity of the mutant to wild-type level. Nicotine degradation of J5 was inhibited markedly by addition of tungstate, a specific antagonist of molybdate. Molybdate at a non-physiologically high concentration (100 μM) fully restored nicotine-degrading activity and recovered growth of the modABC mutant in a nicotine minimal medium. Transcriptional analysis revealed that the expression of modABC was up-regulated at low molybdate concentrations and down-regulated at high moybdate concentrations, which indicated that at least one other system was able to transport molybdate, but with lower affinity. These results suggested that the molybdate transport system was essential to nicotine metabolism in P. putida J5.

Molybdenum Enzymes and How They Support Virulence in Pathogenic Bacteria

“…In most bacteria, the ATP-binding-cassette (ABC)-type molybdate transport system, ModABC, mediates high affinity uptake of molybdate from the environment (Rech et al, 1995;Hu et al, 1997;Imperial et al, 1998;Lawson et al, 1998;Self et al, 2001;Gisin et al, 2010;Perinet et al, 2016;Xia et al, 2018). The substrate-binding protein of this transporter, ModA, is a molybdate-specific, type II periplasmic-binding-protein (PBP2, cl21456) that interacts with the ModB and ModC proteins that form the channel for molybdate import and hydrolyze ATP to provide the energy required for transport, respectively (Hu et al, 1997;Lawson et al, 1998;Self et al, 2001;Santacruz et al, 2006;Hollenstein et al, 2007;Davidson et al, 2008).…”

Selective Biosynthesis of Furoic Acid From Furfural by Pseudomonas Putida and Identification of Molybdate Transporter Involvement in Furfural Oxidation

“…During the inspection of the genome, a molybdate transporter (ModABC, PP_3828–PP_3830, Figure 6A ) attracted our attention. As mentioned above, molybdate transporter had been evidenced critically in detoxification of many aromatic compounds (Blaschke et al, 1991 ; Ganas et al, 2008 ; Xia et al, 2018 ). In view of the facts that FAL and HMF were typical inhibitors to strains (Zaldivar et al, 1999 ; Franden et al, 2013 ), we thus wonder whether molybdate transporter was related to the biotransformation/detoxification of furanic aldehydes.…”

“…Once entering into the cell, molybdate is subsequently incorporated into the complex pathway of molybdenum cofactor biosynthesis and finally to activate molybdoenzymes (Hille et al, 2014 ; Mendel and Leimkühler, 2015 ; Leimkühler and Iobbi-Nivol, 2016 ). Researches had showed that ModABC played a critical role in the detoxification of aromatic compounds, such as nicotine and quinoline (Blaschke et al, 1991 ; Ganas et al, 2008 ; Xia et al, 2018 ). Moreover, molybdate uptake was also involved in aerobic degradation of FA, as a 2-furoyl-CoA dehydrogenase which converted 2-furoyl-CoA into 5-hydroxy-2-furoyl-CoA was confirmed as molybdoenzyme (Koenig and Andreesen, 1989 , 1990 ; Koopman et al, 2010 ).…”

Composition and niche-specific characteristics of microbial consortia colonizing Marsberg copper mine in the Rhenish Massif

“…The oxyanions molybdate and tungstate are taken up through the membrane by the high-affinity ModABC molybdate system along with sulfate ions (Self et al, 2001;Xia et al, 2018;Maupin-Furlow et al, 1995). Sulfate and thiosulfate are taken up by sulfate permeases, carriers belonging to the SulT family, encoded by the cysPTWA operon, and SulP family members (inorganic anion uptake carriers) (Kertesz, 2001).…”