tRNA 2-selenouridine synthase; Involved in the post-transcriptional modification of the uridine at the wobble position (U34) of tRNA(Lys), tRNA(Glu) and tRNA(Gln). Catalyzes the conversion of 2-thiouridine (S2U-RNA) to 2-selenouridine (Se2U-RNA). Acts in a two-step process involving geranylation of 2-thiouridine (S2U) to S-geranyl-2-thiouridine (geS2U) and subsequent selenation of the latter derivative to 2-selenouridine (Se2U) in the tRNA chain.

selenocysteinyl-tRNA-specific translation factor; Translation factor necessary for the incorporation of selenocysteine into proteins. It probably replaces EF-Tu for the insertion of selenocysteine directed by the UGA codon. SelB binds GTP and GDP; Belongs to the TRAFAC class translation factor GTPase superfamily. Classic translation factor GTPase family. SelB subfamily.

Cysteine desulfurase, stimulated by SufE; Cysteine desulfurases mobilize the sulfur from L-cysteine to yield L-alanine, an essential step in sulfur metabolism for biosynthesis of a variety of sulfur-containing biomolecules. Component of the suf operon, which is activated and required under specific conditions such as oxidative stress and iron limitation. Acts as a potent selenocysteine lyase in vitro, that mobilizes selenium from L- selenocysteine. Selenocysteine lyase activity is however unsure in vivo. Belongs to the class-V pyridoxal-phosphate-dependent aminotransferase family. Csd [...]

Thioredoxin reductase, FAD/NAD(P)-binding; Thioredoxin reductase; Belongs to the class-II pyridine nucleotide-disulfide oxidoreductase family.

Cysteine desulfurase (tRNA sulfurtransferase), PLP-dependent; Master enzyme that delivers sulfur to a number of partners involved in Fe-S cluster assembly, tRNA modification or cofactor biosynthesis. Catalyzes the removal of elemental sulfur from cysteine to produce alanine. Functions as a sulfur delivery protein for Fe-S cluster synthesis onto IscU, an Fe-S scaffold assembly protein, as well as other S acceptor proteins. Preferentially binds to disordered IscU on which the Fe-S is assembled, IscU converts to the structured state and then dissociates from IscS to transfer the Fe-S to a [...]

Formate dehydrogenase-H, selenopolypeptide subunit; Decomposes formic acid to hydrogen and carbon dioxide under anaerobic conditions in the absence of exogenous electron acceptors.

DNA topoisomerase III; Releases the supercoiling and torsional tension of DNA, which is introduced during the DNA replication and transcription, by transiently cleaving and rejoining one strand of the DNA duplex. Introduces a single-strand break via transesterification at a target site in duplex DNA. The scissile phosphodiester is attacked by the catalytic tyrosine of the enzyme, resulting in the formation of a DNA- (5'-phosphotyrosyl)-enzyme intermediate and the expulsion of a 3'-OH DNA strand. The free DNA strand then undergoes passage around the unbroken strand, thus removing DNA su [...]

XdhC-CoxI family protein with NAD(P)-binding Rossman fold; Putative synthases.

seryl-tRNA synthetase; Catalyzes the attachment of serine to tRNA(Ser). Is also able to aminoacylate tRNA(Sec) with serine, to form the misacylated tRNA L- seryl-tRNA(Sec), which will be further converted into selenocysteinyl- tRNA(Sec).