Here we determine the genetic basis of lactate racemization in Lactobacillus plantarum. 
Lactobacillus plantarum
Lactate racemase is a nickel-dependent enzyme activated by a widespread maturation system.Racemases catalyse the inversion of stereochemistry in biological molecules, giving the organism the ability to use both isomers.  Among them, lactate racemase remains unexplored due to its intrinsic instability and lack of molecular characterization.  Genomic investigations reveal the wide distribution of the lactate racemase system among prokaryotes, showing the high significance of both lactate enantiomers in carbon metabolism.  The even broader distribution of the nickel-based maturation system suggests a function beyond activation of the lactate racemase and possibly linked with other undiscovered nickel-dependent enzymes.
lactate racemase
In addition, we decipher the process leading to an active enzyme, which involves the activation of the apo-enzyme by a single nickel-containing maturation protein that requires preactivation by two other accessory proteins. 
nickel-containing maturation protein
In addition, we decipher the process leading to an active enzyme, which involves the activation of the apo-enzyme by a single nickel-containing maturation protein that requires preactivation by two other accessory proteins. 
accessory proteins