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.[3]
Protein structure
Selenoprotein T contains a selenocysteine (Sec) residue at its active site.
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