Evolutionary conservation among biotin enzymes

The biotin-dependent carboxylases are a group of enzymes with a diverse set of functions but with many common features and mechanisms. In vertebrates, there are four known biotin-containing enzymes that play important roles in lipogenesis, gluconeogenesis, and amino acid metabolism. In prokaryotes, they have additional roles being energy transducers in several obligate anaerobic species. Their focus will be primarily on the evolutionary conservation of structure by biotin enzymes. The end result is to pump sodium against a concentration gradient. Thus, this class of biotin enzymes serves as an important energy transducer that does not require ATP.