This family consists of proline racemase (EC 5.1.1.4) proteins which catalyze the interconversion of L- and D-proline in bacteria. This family also contains several similar eukaryotic proteins including Swiss:Q9NCP4 a sequence with B-cell mitogenic properties which has been characterized as a co-factor-independent proline racemase.
Jiyao W et al.(2023). "The conserved domain database in 2023.",