IUBMB Enzyme Nomenclature


Accepted name: O-phospho-L-seryl-tRNASec:L-selenocysteinyl-tRNA synthase

Reaction: O-phospho-L-seryl-tRNASec + selenophosphate + H2O = L-selenocysteinyl-tRNASec + 2 phosphate

Other name(s): MMPSepSecS; SepSecS; SLA/LP; O-phosphoseryl-tRNA:selenocysteinyl-tRNA synthase; O-phospho-L-seryl-tRNA:L-selenocysteinyl-tRNA synthase

Systematic name: selenophosphate:O-phospho-L-seryl-tRNASec selenium transferase

Comments: A pyridoxal-phosphate protein [4]. In archaea and eukarya selenocysteine formation is achieved by a two-step process: EC (O-phosphoseryl-tRNASec kinase) phosphorylates the endogenous L-seryl-tRNASec to O-phospho-L-seryl-tRNASec, and then this misacylated amino acid-tRNA species is converted to L-selenocysteinyl-tRNASec by Sep-tRNA:Sec-tRNA synthase.

Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number:


1. Palioura, S., Sherrer, R.L., Steitz, T.A., Soll, D. and Simonovic, M. The human SepSecS-tRNASec complex reveals the mechanism of selenocysteine formation. Science 325 (2009) 321-325. [PMID: 19608919]

2. Araiso, Y., Palioura, S., Ishitani, R., Sherrer, R.L., O'Donoghue, P., Yuan, J., Oshikane, H., Domae, N., Defranco, J., Soll, D. and Nureki, O. Structural insights into RNA-dependent eukaryal and archaeal selenocysteine formation. Nucleic Acids Res. 36 (2008) 1187-1199. [PMID: 18158303]

3. Aeby, E., Palioura, S., Pusnik, M., Marazzi, J., Lieberman, A., Ullu, E., Soll, D. and Schneider, A. The canonical pathway for selenocysteine insertion is dispensable in Trypanosomes. Proc. Natl. Acad. Sci. USA 106 (2009) 5088-5092. [PMID: 19279205]

4. Yuan, J., Palioura, S., Salazar, J.C., Su, D., O'Donoghue, P., Hohn, M.J., Cardoso, A.M., Whitman, W.B. and Soll, D. RNA-dependent conversion of phosphoserine forms selenocysteine in eukaryotes and archaea. Proc. Natl. Acad. Sci. USA 103 (2006) 18923-18927. [PMID: 17142313]

[EC created 2009, modified 2014]

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