Novel Selenoproteins Identified in Silico andin Vivo by Using a Conserved RNA Structural Motif

摘要: Selenocysteine is incorporated into selenoproteins by an in-frame UGA codon whose readthrough requires the selenocysteine insertion sequence (SECIS), a conserved hairpin in 3'-untranslated region of eukaryotic selenoprotein mRNAs. To identify new selenoproteins, we developed strategy that obviates need for prior amino acid information. A computational screen was used to scan nucleotide data bases sequences presenting potential SECIS secondary structure. The computer-selected hairpins were then assayed vivo their functional capacities, and cDNAs corresponding winners identified. Four them encoded novel as confirmed experiments. Among these, SelZf1 SelZf2 share common domain with mitochondrial thioredoxin reductase-2. three proteins, however, possess distinct N-terminal domains. We found another protein, SelX, displays similarity protein involved bacterial pilus formation. For first time, four discovered based on RNA directing incorporation.