Selenoprotein H (SELH)

SELH encodes a selenoprotein, which contains a selenocysteine (Sec) residue at its active site. The selenocysteine is encoded by the UGA codon that normally signals translation termination. The 3""" UTR of selenoprotein genes have a common stem-loop structure, the sec insertion sequence (SECIS), that is necessary for the recognition of UGA as a Sec codon rather than as a stop signal. The exact function of this gene is not known, however, selenoproteins are thought to be responsible for most biomedical effects of dietary selenium. By searching databases using a SECIS-based method to identify putative selenoproteins, Kryukov et al. (2003) identified SELH. The deduced 122-amino acid globular protein contains a sec at position 44, just upstream of an alpha helix. SELH mRNA was detected in a variety of tissues and cell types.