The unique tRNASec and its role in selenocysteine biosynthesis.
Vitor Hugo Balasco SerrãoIvan Rosa SilvaMarco Tulio Alves da SilvaJéssica Fernandes ScortecciAdriano de Freitas FernandesOtavio Henrique ThiemannPublished in: Amino acids (2018)
Selenium (Se) is an essential trace element for several organisms and is mostly present in proteins as L-selenocysteine (Sec or U). Sec is synthesized on its L-seryl-tRNASec to produce Sec-tRNASec molecules by a dedicated selenocysteine synthesis machinery and incorporated into selenoproteins at specified in-frame UGA codons. UGA-Sec insertion is signaled by an mRNA stem-loop structure called the SElenoCysteine Insertion Sequence (SECIS). tRNASec transcription regulation and folding have been described showing its importance to Sec biosynthesis. Here, we discuss structural aspects of Sec-tRNASec and its role in Sec biosynthesis as well as Sec incorporation into selenoproteins. Defects in the Sec biosynthesis or incorporation pathway have been correlated with pathological conditions.
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