Thought to be a D-serine dehydratase, however it does not complement a dsdA (D-serine dehydratase) mutant in strain CFT073, suggesting it may not have that function (PubMed:26727373). 40-fold induced under conditions that maximally induce expression of the large pathogenicity island (PAI) also called the locus of effacement (LEE); part of the dlsT-yhaM operon. Slightly induced by D-serine. No effect on protein secretion by the type III secretion system (TTSS) encoded in the locus of effacement (LEE). Belongs to the UPF0597 family.