ID   GRDA_SYMTH              Reviewed;         155 AA.
AC   Q67KE6;
DT   19-SEP-2006, integrated into UniProtKB/Swiss-Prot.
DT   26-FEB-2008, sequence version 2.
DT   02-JUN-2021, entry version 94.
DE   RecName: Full=Glycine/sarcosine/betaine reductase complex component A;
DE            EC=1.21.4.2;
DE            EC=1.21.4.3;
DE            EC=1.21.4.4;
DE   AltName: Full=Selenoprotein PA;
DE   AltName: Full=Thioredoxin reductase complex selenoprotein A;
GN   Name=grdA; OrderedLocusNames=STH2869;
OS   Symbiobacterium thermophilum (strain T / IAM 14863).
OC   Bacteria; Firmicutes; Clostridia; Eubacteriales; Symbiobacteriaceae;
OC   Symbiobacterium.
OX   NCBI_TaxID=292459;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=T / IAM 14863;
RX   PubMed=15383646; DOI=10.1093/nar/gkh830;
RA   Ueda K., Yamashita A., Ishikawa J., Shimada M., Watsuji T., Morimura K.,
RA   Ikeda H., Hattori M., Beppu T.;
RT   "Genome sequence of Symbiobacterium thermophilum, an uncultivable bacterium
RT   that depends on microbial commensalism.";
RL   Nucleic Acids Res. 32:4937-4944(2004).
CC   -!- FUNCTION: In the first step of glycine, betaine and sarcosine
CC       reductases, the substrate is bound to component PB via a Schiff base
CC       intermediate. Then the PB-activated substrate is nucleophilically
CC       attacked by the selenol anion of component PA to transform it to a
CC       carboxymethylated selenoether and the respective amine. By action of
CC       component PC, acetyl phosphate is formed, leaving component PA in its
CC       oxidized state. Finally component PA becomes reduced by the thioredoxin
CC       system to start a new catalytic cycle of reductive deamination (By
CC       similarity). {ECO:0000250}.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=[thioredoxin]-disulfide + acetyl phosphate + H2O + NH4(+) =
CC         [thioredoxin]-dithiol + glycine + H(+) + phosphate;
CC         Xref=Rhea:RHEA:12232, Rhea:RHEA-COMP:10698, Rhea:RHEA-COMP:10700,
CC         ChEBI:CHEBI:15377, ChEBI:CHEBI:15378, ChEBI:CHEBI:22191,
CC         ChEBI:CHEBI:28938, ChEBI:CHEBI:29950, ChEBI:CHEBI:43474,
CC         ChEBI:CHEBI:50058, ChEBI:CHEBI:57305; EC=1.21.4.2;
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=[thioredoxin]-disulfide + acetyl phosphate + H2O + methylamine
CC         = [thioredoxin]-dithiol + H(+) + phosphate + sarcosine;
CC         Xref=Rhea:RHEA:12825, Rhea:RHEA-COMP:10698, Rhea:RHEA-COMP:10700,
CC         ChEBI:CHEBI:15377, ChEBI:CHEBI:15378, ChEBI:CHEBI:22191,
CC         ChEBI:CHEBI:29950, ChEBI:CHEBI:43474, ChEBI:CHEBI:50058,
CC         ChEBI:CHEBI:57433, ChEBI:CHEBI:59338; EC=1.21.4.3;
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=[thioredoxin]-disulfide + acetyl phosphate + H2O +
CC         trimethylamine = [thioredoxin]-dithiol + glycine betaine + H(+) +
CC         phosphate; Xref=Rhea:RHEA:11848, Rhea:RHEA-COMP:10698, Rhea:RHEA-
CC         COMP:10700, ChEBI:CHEBI:15377, ChEBI:CHEBI:15378, ChEBI:CHEBI:17750,
CC         ChEBI:CHEBI:22191, ChEBI:CHEBI:29950, ChEBI:CHEBI:43474,
CC         ChEBI:CHEBI:50058, ChEBI:CHEBI:58389; EC=1.21.4.4;
CC   -!- SUBUNIT: Monomer. Component of the glycine, sarcosine and betaine
CC       reductase complexes, together with components B and C (By similarity).
CC       {ECO:0000250}.
CC   -!- SIMILARITY: Belongs to the GrdA family. {ECO:0000305}.
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DR   EMBL; AP006840; BAD41852.1; -; Genomic_DNA.
DR   STRING; 292459.STH2869; -.
DR   KEGG; sth:STH2869; -.
DR   eggNOG; ENOG50313TT; Bacteria.
DR   HOGENOM; CLU_142275_0_0_9; -.
DR   OMA; FASTECF; -.
DR   Proteomes; UP000000417; Chromosome.
DR   GO; GO:0030700; C:glycine reductase complex; IEA:InterPro.
DR   GO; GO:0033795; F:betaine reductase activity; IEA:UniProtKB-EC.
DR   GO; GO:0030699; F:glycine reductase activity; IEA:UniProtKB-UniRule.
DR   GO; GO:0033794; F:sarcosine reductase activity; IEA:UniProtKB-EC.
DR   HAMAP; MF_00826; GRDA; 1.
DR   InterPro; IPR006812; GRDA.
DR   Pfam; PF04723; GRDA; 1.
DR   PIRSF; PIRSF000181; Grc_selenoprot_A; 1.
PE   3: Inferred from homology;
KW   Oxidoreductase; Reference proteome; Selenocysteine.
FT   CHAIN           1..155
FT                   /note="Glycine/sarcosine/betaine reductase complex
FT                   component A"
FT                   /id="PRO_0000249763"
FT   ACT_SITE        43
FT                   /evidence="ECO:0000250"
FT   NON_STD         43
FT                   /note="Selenocysteine"
FT                   /evidence="ECO:0000305"
SQ   SEQUENCE   155 AA;  16786 MW;  6B4BC016ADAF3A7E CRC64;
     MELKGKKAII LGDRDGIPGP ALEACVRSAG AEVVFASTEC FVUTSAGAMD MENQRRVKEL
     AEKYPKEDLV VILGGAEAEA SGLAAETVSN GDPAWAGPLA GVQLGLKAYH IFEPEIKEQI
     DPNVYEEQVS LMEMVLDVEA IVQEVRSIRE KYAAW