arcD, the first gene of the arc operon for anaerobic arginine catabolism in Pseudomonas aeruginosa, encodes an arginine-ornithine exchanger

Abstract

In the absence of oxygen and nitrate, Pseudomonas aeruginosa metabolizes arginine via the arginine deiminase pathwayt, which allows slow growth on rich media. The conversion of arginine to ornithine, C02, and NH3 is coupled to the production of ATP from ADP. The enzymes of the arginine deiminase pathway are organized in the arcDABC operon. The arcD gene encodes a hydrophobic polytopic membrane protein.Translocation of arginine and ornithine in membrane vesicles derived from an Escherichia coli strain harboring a recombinant plasmid carrying the arcD gene was studied. Arginine and ornithine uptake was coupled to the proton motive force with a bias toward the transmembrane electrical potential. Accumulated ornithine was readily exchangeable for external arginine or lysine. The exchange was several orders of magnitude faster than proton motive force-driven transport. The ArcD protein was reconstituted in proteoliposomes after detergent solubilization of membrane vesicles. These proteoliposomes mediate a stoichiometric exchange between arginine and ornithine. It is concluded that the ArcD protein is a transport system that catalyzes an electroneutral exchange between arginine and ornithine to allow high-efficiency energy conversion in the arginine deiminase pathway.To survive anaerobiosis in the absence of nitrate as a terminal electron acceptor, Pseudomonas aeruginosa uses arginine as an energy source for viability, motility, and slow growth on rich media (31, 34). Arginine is metabolized in the arginine deiminase pathway (for a review, see reference 6). This pathway includes three cytoplasmic enzymes: (i) arginine deiminase, which catalyzes the conversion of arginine into citrulline and amnmonia (in an essentially irreversible reaction); (ii) catabolic ornithine carbamoyl transferase, which catalyzes the reaction of citrullinen with Pi to yield ornithine and carbamoyl phosphate; and (iii) carbamate kinase, which converts carbamoyl phosphate and ADP to ATP, CO2. and ammonia. These enzymes are encoded by the arcA, arcB, and arcC genes, respectively (34). The arcABC genes have been cloned and sequenced (2, 3) and are organized in an operon (24,30). The arc operon is under control of a positive regulatory protein, ANR, an FNR-like protein of P. aenrginosa (16,18,37)

A Winogradsky-based culture system shows an association between microbial fermentation and cystic fibrosis exacerbation

“…The behavior of P. aeruginosa-and Climax Community-dominated samples matches much of what is recorded in the literature: that the organism grows anaerobically using denitrification in antibiotic-resistant biofilms (Worlitzsch et al, 2002;Palmer et al, 2005;Hogardt and Heesemann, 2010;Schobert and Jahn, 2010). The elevated pH in the media may be due to the production of ammonia from amino-acid breakdown, often observed with P. aeruginosa grown in a CF state (Verhoogt et al, 1992;Barth and Pitt, 1996;Thomas et al, 2000;Frimmersdorf et al, 2010), and previously demonstrated to accumulate in WinCF capillary tubes after the growth of CF microbes . Thus the P. aeruginosa WinCF responses may reflect the true physiology of this microbe and others like it in the CF lung and is in stark contrast to the physiology of the Attack Community during exacerbation events.…”

Generation of a proton motive force by histidine decarboxylation and electrogenic histidine/histamine antiport in Lactobacillus buchneri

“…The gene coding for lysine decarboxylase is located in an operon structure together with a gene which seems to code for a transport protein. On the basis of homology with the arginine/ornithine antiporter of P. aeruginosa (26), this transport protein was predicted to be a lysine/cadaverine antiporter.…”

Mammalian integral membrane receptors are homologous to facilitators and antiporters of yeast, fungi, and eubacteria

“…In contrast, the ArcD protein, which specifies an arginine/ornithine antiporter of Z? aeruginosa (Luthi et al, 1990;Verhoogt et al, 1992) and falls into the class of bacterial precursor/product antiporters discussed by Poolman (1990), is more divergent. The ArcD antiporter of P. aeruginosa is most similar to the two E. coli polyamine permeases, i.e., the putrescine/ornithine antiporter (PotE: Kashiwagi et al, 1991Kashiwagi et al, , 1992 and the putative cadaverine/lysine antiporter (CadB : Meng & Bennett, 1992;Watson et al, 1992) (24% identity; comparison scores of 23-33 standard deviations, see Table 1).…”