SPCS_XENTR
ID SPCS_XENTR Reviewed; 506 AA.
AC Q28EN2;
DT 01-MAY-2007, integrated into UniProtKB/Swiss-Prot.
DT 04-APR-2006, sequence version 1.
DT 03-AUG-2022, entry version 73.
DE RecName: Full=O-phosphoseryl-tRNA(Sec) selenium transferase;
DE EC=2.9.1.2 {ECO:0000250|UniProtKB:Q9HD40};
DE AltName: Full=Selenocysteine synthase;
DE Short=Sec synthase;
DE AltName: Full=Selenocysteinyl-tRNA(Sec) synthase;
DE AltName: Full=Sep-tRNA:Sec-tRNA synthase;
DE Short=SepSecS;
DE AltName: Full=UGA suppressor tRNA-associated protein;
GN Name=sepsecs; ORFNames=TGas010o23.1;
OS Xenopus tropicalis (Western clawed frog) (Silurana tropicalis).
OC Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; Amphibia;
OC Batrachia; Anura; Pipoidea; Pipidae; Xenopodinae; Xenopus; Silurana.
OX NCBI_TaxID=8364;
RN [1]
RP NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA].
RC TISSUE=Gastrula;
RG Sanger Xenopus tropicalis EST/cDNA project;
RL Submitted (OCT-2006) to the EMBL/GenBank/DDBJ databases.
CC -!- FUNCTION: Converts O-phosphoseryl-tRNA(Sec) to selenocysteinyl-
CC tRNA(Sec) required for selenoprotein biosynthesis.
CC {ECO:0000250|UniProtKB:Q9HD40}.
CC -!- CATALYTIC ACTIVITY:
CC Reaction=H2O + O-phospho-L-seryl-tRNA(Sec) + selenophosphate = L-
CC selenocysteinyl-tRNA(Sec) + 2 phosphate; Xref=Rhea:RHEA:25041,
CC Rhea:RHEA-COMP:9743, Rhea:RHEA-COMP:9947, ChEBI:CHEBI:15377,
CC ChEBI:CHEBI:16144, ChEBI:CHEBI:43474, ChEBI:CHEBI:78551,
CC ChEBI:CHEBI:78573; EC=2.9.1.2;
CC Evidence={ECO:0000250|UniProtKB:Q9HD40};
CC -!- COFACTOR:
CC Name=pyridoxal 5'-phosphate; Xref=ChEBI:CHEBI:597326;
CC Evidence={ECO:0000250|UniProtKB:Q9HD40};
CC -!- PATHWAY: Aminoacyl-tRNA biosynthesis; selenocysteinyl-tRNA(Sec)
CC biosynthesis; selenocysteinyl-tRNA(Sec) from L-seryl-tRNA(Sec)
CC (archaeal/eukaryal route): step 2/2. {ECO:0000250|UniProtKB:Q9HD40}.
CC -!- SUBUNIT: Homotetramer formed by a catalytic dimer and a non-catalytic
CC dimer serving as a binding platform that orients tRNASec for catalysis.
CC Each tetramer binds the CCA ends of two tRNAs which point to the active
CC sites of the catalytic dimer. {ECO:0000250|UniProtKB:Q9HD40}.
CC -!- SUBCELLULAR LOCATION: Cytoplasm {ECO:0000250|UniProtKB:Q9HD40}.
CC -!- SIMILARITY: Belongs to the SepSecS family. {ECO:0000305}.
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DR EMBL; CR848159; CAJ83391.1; -; mRNA.
DR RefSeq; NP_001004947.2; NM_001004947.2.
DR AlphaFoldDB; Q28EN2; -.
DR SMR; Q28EN2; -.
DR DNASU; 448354; -.
DR GeneID; 448354; -.
DR KEGG; xtr:448354; -.
DR CTD; 51091; -.
DR Xenbase; XB-GENE-962222; sepsecs.
DR InParanoid; Q28EN2; -.
DR OrthoDB; 680116at2759; -.
DR UniPathway; UPA00906; UER00898.
DR Proteomes; UP000008143; Chromosome 1.
DR Proteomes; UP000790000; Unplaced.
DR GO; GO:0005737; C:cytoplasm; IEA:UniProtKB-SubCell.
DR GO; GO:0098621; F:phosphoseryl-selenocysteinyl-tRNA selenium transferase activity; IEA:UniProtKB-EC.
DR GO; GO:0000049; F:tRNA binding; IBA:GO_Central.
DR GO; GO:0001514; P:selenocysteine incorporation; IBA:GO_Central.
DR GO; GO:0097056; P:selenocysteinyl-tRNA(Sec) biosynthetic process; IEA:UniProtKB-UniPathway.
DR Gene3D; 3.40.640.10; -; 1.
DR InterPro; IPR015424; PyrdxlP-dep_Trfase.
DR InterPro; IPR015421; PyrdxlP-dep_Trfase_major.
DR InterPro; IPR019872; Sec-tRNA_Se_transferase.
DR InterPro; IPR008829; SepSecS/SepCysS.
DR PANTHER; PTHR12944; PTHR12944; 1.
DR Pfam; PF05889; SepSecS; 1.
DR PIRSF; PIRSF017689; SepSecS; 1.
DR SUPFAM; SSF53383; SSF53383; 1.
DR TIGRFAMs; TIGR03531; selenium_SpcS; 1.
PE 2: Evidence at transcript level;
KW Cytoplasm; Protein biosynthesis; Pyridoxal phosphate; Reference proteome;
KW RNA-binding; Selenium; Transferase; tRNA-binding.
FT CHAIN 1..506
FT /note="O-phosphoseryl-tRNA(Sec) selenium transferase"
FT /id="PRO_0000285287"
FT REGION 1..44
FT /note="Tetramerization"
FT /evidence="ECO:0000250|UniProtKB:Q9HD40"
FT REGION 96..106
FT /note="Phosphate loop (P-loop)"
FT /evidence="ECO:0000250|UniProtKB:Q9HD40"
FT BINDING 75
FT /ligand="pyridoxal 5'-phosphate"
FT /ligand_id="ChEBI:CHEBI:597326"
FT /evidence="ECO:0000250|UniProtKB:Q9HD40"
FT BINDING 97
FT /ligand="substrate"
FT /evidence="ECO:0000250|UniProtKB:Q9HD40"
FT BINDING 98
FT /ligand="substrate"
FT /evidence="ECO:0000250|UniProtKB:Q9HD40"
FT BINDING 105
FT /ligand="substrate"
FT /evidence="ECO:0000250|UniProtKB:Q9HD40"
FT BINDING 271
FT /ligand="tRNA"
FT /ligand_id="ChEBI:CHEBI:17843"
FT /ligand_part="tRNA variable arm"
FT /evidence="ECO:0000250|UniProtKB:Q9HD40"
FT BINDING 313
FT /ligand="substrate"
FT /evidence="ECO:0000250|UniProtKB:Q9HD40"
FT BINDING 398
FT /ligand="tRNA"
FT /ligand_id="ChEBI:CHEBI:17843"
FT /ligand_part="tRNA discriminator base"
FT /evidence="ECO:0000250|UniProtKB:Q9HD40"
FT BINDING 463
FT /ligand="tRNA"
FT /ligand_id="ChEBI:CHEBI:17843"
FT /ligand_part="tRNA acceptor arm"
FT /evidence="ECO:0000250|UniProtKB:Q9HD40"
FT SITE 74
FT /note="May act as a substrate filter by repelling compounds
FT with a negatively charged alpha-carboxylate"
FT /evidence="ECO:0000250|UniProtKB:Q6P6M7"
FT MOD_RES 284
FT /note="N6-(pyridoxal phosphate)lysine"
FT /evidence="ECO:0000250|UniProtKB:Q9HD40"
SQ SEQUENCE 506 AA; 55735 MW; C00F2E48DFB83C38 CRC64;
MEHESFKASE RLVTPAYIRQ GREARRMHEQ LVRQLVEQGK CPKEPWDEST IEIFLNELAV
MDSNNFLGNC GVGEREGRVA SGMVSRRHYR LIHGIGRSGD ISAIQPKAAG SSVLNKLTNS
MVLDIIRLAG VRTASSCFVV PMATGMSLTL CFLTLRHKRP KAKYIIWPRI DQKSCFKSMI
TAGFEPVVIE NVLEGDELRT DLDAVEAKIT ELGAENILCV HSTTSCFAPR VPDRVEELAV
ICKKYEIPHV VNNAYGVQSS KCMHLIQQGA RVGRIDAFVQ SLDKNFMVPV GGAVIAGFSD
SFVQEISKMY PGRASASPSL DVLITLLSLG ASGYNKLLKE RKEMFVYLSS ELKKLAKELN
ERLLETPHNP ISLALSLTSL SEQSGSAVTQ LGSMLFTRQV SGARVVPLGT SQTINGYVFK
GFMSHSNNYP CAYLNAASAI CIKKQDVDMF IKRLDKCLRL CKKEKHLAKD EPRCAQQTTE
DDVAELAQGL GDVLQGETAS ELLLSG
