Phosphoserine (abbreviated as SEP or J) is an ester of serine and phosphoric acid. Phosphoserine is a component of many proteins as the result of posttranslational modifications.[1] The phosphorylation of the alcohol functional group in serine to produce phosphoserine is catalyzed by various types of kinases.[2][3] Through the use of technologies that utilize an expanded genetic code, phosphoserine can also be incorporated into proteins during translation.[4][5][6]
It is a normal metabolite found in human biofluids.[7]
Phosphoserine has three potential coordination sites (carboxyl, amine and phosphate group) Determination of the mode of coordination between phosphorylated ligands and metal ions occurring in an organism is a first step to explain the function of the phosphoserine in bioinorganic processes.[8][9]