D-serine = NH4(+) + pyruvate Monomer. Initially shown to have a 5-6 hour lag phase when grown in human urine, bacteria are initially rounded and swollen but are close to wild-type in morphology by 24 hours and to be more competitive than wild-type in mouse infection (PubMed:12823810). The wild-type (wt) control was later shown to have an amber mutation in rpoS; when the dsdA gene is disrupted in a strain wt for rpoS a growth defect in human urine, lack of growth on minimal medium with D-serine and no difference in growth in a mouse infection model was seen (PubMed:26366567). Single deletion, grows on D-alanine but not D-serine or D-serine plus glycerol (PubMed:16952954). E.coli CFT073, a uropathogenic strain (UPEC), was originally isolated from urine, which has a high concentration of D-serine. D-serine is toxic to bacteria. The ability to take up D-serine coupled with the activity of this enzyme may allow use of this amino acid as a carbon source in a sugar-poor environment. Belongs to the serine/threonine dehydratase family. DsdA subfamily.