A biotin-dependent sodium pump: glutaconyl-CoA decarboxylase from Acidaminococcus fermentans.
The decarboxylation of glutaconyl-CoA to crotonyl-CoA in the anaerobic bacterium Acidaminococcus fermentans is catalysed by a membrane-bound, biotin-dependent enzyme which requires Na+ for activity. Inverted vesicles from A. fermentans accumulated Na+ only if glutaconyl-CoA was decarboxylated. The Na+ uptake was inhibited by avidin but not by the avidin biotin complex. Detergents and ionophores such as monensin also prevented the Na+ transport. The results indicate that the enzyme is able to convert the free energy of decarboxylation (delta Go' approximately equal to -30 kJ/mol) into a Na+ gradient.
D001360:Avidin / Q000494:pharmacology; D001710:Biotin / Q000502:physiology*; D002262:Carboxy-Lyases / Q000378:metabolism*; D005977:Glutarates / Q000378:metabolism; D006089:Gram-Negative Anaerobic Bacteria; D007473:Ion Channels / Q000378:metabolism*; D008985:Monensin / Q000494:pharmacology; D017830:Octoxynol; D011092:Polyethylene Glycols / Q000494:pharmacology; D012964:Sodium / Q000378:metabolism*
D005977:Glutarates; D007473:Ion Channels; D001360:Avidin; C010971:glutaconic acid; D011092:Polyethylene Glycols; D001710:Biotin; D017830:Octoxynol; D008985:Monensin; D012964:Sodium; D002262:Carboxy-Lyases; C023060:glutaconyl CoA decarboxylase