3-Hydroxyaspartic acid

3-Hydroxyaspartic acid (three letter abbreviation: Hya) also known as beta-hydroxyaspartic acid is derivative of aspartic acid which has been hydroxylated at position-3. The adjacent image shows L -threo-3-Hydroxyaspartate. The conjugated acid of 3-hydroxyaspartic acid is 3-hydroxyaspartate.

Structure
Similarly to proteinogenic isoleucine and threonine, 3-hydroxyaspartic acid contains two chiral centers. As such, it can exist in 4 stereoisomers, which form two pairs of enantiomers.

Function
The Hya amino acid residue is sometimes contained in EGF-like domains such as Vitamin K-dependent coagulation plasma proteins including protein C.

D -threo-3-Hydroxyaspartate is a part of the siderophore ornibactin.