SEPSECS Mouse
AA986712, D5Ertd135e, SecS, SLA, SLA/LP autoantigen, SLA-p35, Selenocysteinyl-tRNA(Sec) synthase, Selenocysteine synthase, Liver-pancreas antigen, Soluble liver antigen, Sec synthase, UGA suppressor tRNA-associated protein, SepSecS.
Description
SEPSECS produced in E.Coli is a single, non-glycosylated polypeptide chain containing 527 amino acids (1-504 a.a.) and having a molecular mass of 57.7kDa.
SEPSECS is fused to a 23 amino acid His-tag at N-terminus & purified by proprietary chromatographic techniques.
Product Specs
AA986712, D5Ertd135e, SecS, SLA, SLA/LP autoantigen, SLA-p35, Selenocysteinyl-tRNA(Sec) synthase, Selenocysteine synthase, Liver-pancreas antigen, Soluble liver antigen, Sec synthase, UGA suppressor tRNA-associated protein, SepSecS.
MGSSHHHHHH SSGLVPRGSH MGSMNPESFA AGERRVSPAY VRQGCEARRA HEHLIRLLLE QGKCPEDGWD ESTLELFLHE LAVMDSNNFL GNCGVGEREG RVASALVARR HYRFIHGIGR SGDISAVQPK AAGSSLLNKI TNSLVLNVIK LAGVHSVASC FVVPMATGMS LTLCFLTLRH
KRPKAKYIIW PRIDQKSCFK SMVTAGFEPV VIENVLEGDE LRTDLKAVEA KIQELGPEHI LCLHSTTACF APRVPDRLEE LAVICANYDI PHVVNNAYGL QSSKCMHLIQ QGARVGRIDA FVQSLDKNFM VPVGGAIIAG FNEPFIQDIS KMYPGRASAS PSLDVLITLL SLGCSGYRKL
LKERKEMFVY LSTQLKKLAE AHNERLLQTP HNPISLAMTL KTIDGHHDKA VTQLGSMLFT RQVSGARAVP LGNVQTVSGH TFRGFMSHAD NYPCAYLNAA AAIGMKMQDV DLFIKRLDKC LNIVRKEQTR ASVVSGADRN KAEDADIEEM ALKLDDVLGD VGQGPAL.
Product Science Overview
Selenocysteinyl-tRNA(Sec) synthase, often abbreviated as SepSecS, is a crucial enzyme involved in the biosynthesis of selenocysteine (Sec), the 21st amino acid. This enzyme is particularly significant in the context of selenoprotein synthesis, where selenocysteine is incorporated into proteins at specific UGA codons, which typically signal stop codons in the genetic code .
Selenocysteine is synthesized on its cognate transfer RNA (tRNA), known as tRNA(Sec). The biosynthesis of selenocysteine involves several steps:
- Aminoacylation: Initially, tRNA(Sec) is aminoacylated with serine by seryl-tRNA synthetase (SerRS) to form Ser-tRNA(Sec) .
- Phosphoseryl-tRNA(Sec) Formation: The serine attached to tRNA(Sec) is then phosphorylated to form O-phosphoseryl-tRNA(Sec) (Sep-tRNA(Sec)) .
- Selenocysteinyl-tRNA(Sec) Formation: Finally, SepSecS catalyzes the conversion of Sep-tRNA(Sec) to selenocysteinyl-tRNA(Sec) (Sec-tRNA(Sec)) . This step is pyridoxal phosphate-dependent and involves the replacement of the phosphate group with selenium .
The crystal structure of SepSecS in complex with tRNA(Sec), phosphoserine, and thiophosphate has provided significant insights into the enzyme’s mechanism. The structure reveals that two tRNA(Sec) molecules bind to each SepSecS tetramer through their 13-base pair acceptor-TPsiC arm . This binding likely induces a conformational change in the enzyme’s active site, allowing the proper orientation of phosphoserine for the reaction to occur .
Selenocysteine is an essential component of several selenoproteins, which play critical roles in various biological processes, including antioxidant defense, thyroid hormone metabolism, and redox homeostasis . Defects in the biosynthesis or incorporation of selenocysteine can lead to various pathological conditions .
The recombinant production of mouse SepSecS involves cloning the gene encoding the enzyme into an expression vector, followed by expression in a suitable host system, such as E. coli. The recombinant enzyme can then be purified using affinity chromatography techniques. This recombinant enzyme is valuable for studying the detailed mechanisms of selenocysteine biosynthesis and for potential therapeutic applications.
