1R0M

N-succinylamino acid racemase (NAAAR) catalyses the racemisation of N-succinyl-D/L-amino acids, as part of a pathway for the conversion of D- to L-amino acids. NAAARs act on a broad range of N-acylamino acids rather than amino acids. This function is of significant interest in industry where enantiopure amino acids are inportant as chiral building blocks for antibiotics, herbicides, and drugs. The experimentally characterised enzyme from Geobacillus kaustophilus efficiently catalyses the racemisation of hydrophobic, polar, and some basic N-succinyl-D/L-amino acids.

These enzymes are members of the enolase superfamily and highly similar to enzymes in the o-succinylbenzoate synthase family, and some may also function biologically as OSBSs. Although the reaction catalyzed by this family is similar to that catalyzed by the NSAR2 family (differing only in the preference of N-succinyl arginine/lysine for NSAR2 versus N-succinyl hydrophobic amino acids for NSAR), phylogenetic analysis suggests that these two families have independent evolutionary origins within the enolase superfamily. Not surprisingly, the amino acids responsible for substrate recognition appear to differ between the two families.