This gene encodes an enzyme that synthesizes selenophosphate from selenide and ATP. Selenophosphate is the selenium donor used to synthesize selenocysteine (Sec) that is co-translationally incorporated into selenoproteins at in-frame UGA codons, which normally signal translation termination. This protein itself contains a Sec residue in its predicted active site. The 3' UTR of this gene has a stem-loop secondary structure called a selenocysteine insertion sequence (SECIS) element, which is necessary for the recognition of UGA as a Sec codon rather than as a stop signal. [provided by RefSeq, Jul 2008]

