serine racemase; D-serine ammonia-lyase; D-serine dehydratase; L-serine ammonia-lyase (SRR)

Function

• catalyzes synthesis of D-serine from L-serine
• D-serine is a coagonist with glutamate at NMDA receptors
• as dehydratase activity towards both L-serine & D-serine
• allosterically activated by Mg+2, & possibly also other divalent metal cations
• allosterically activated by ATP, ADP or GTP.

Kinetic parameters:

• KM=6.5 mM for L-serine

L-serine = D-serine

L-serine = pyruvate + NH3

D-serine = pyruvate + NH3

Cofactor: pyridoxal phosphate

Inhibition:

• competitively inhibited by malonate
• S-nitrosylated, leading to decrease the enzyme activity

Structure

• homodimer
• belongs to the serine/threonine dehydratase family

Expression

• expressed in brain:
  • expressed hippocampus & corpus callosum > substantia nigra & caudate > amygdala, thalamus, & subthalamic nuclei
• expressed in heart, skeletal muscle, kidney & liver

More general terms

• isomerase

Database

• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=63826
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:63826
• OMIM: https://mirror.omim.org/entry/606477
• UniProt: http://www.uniprot.org/uniprot/Q9GZT4.html