ID   GRDG_PEPAC              Reviewed;         428 AA.
AC   O86185;
DT   16-JAN-2004, integrated into UniProtKB/Swiss-Prot.
DT   01-NOV-1998, sequence version 1.
DT   25-MAY-2022, entry version 47.
DE   RecName: Full=Sarcosine reductase complex component B subunit alpha;
DE            EC=1.21.4.3;
DE   AltName: Full=Selenoprotein PB alpha;
DE   Contains:
DE     RecName: Full=Sarcosine reductase complex component B beta chain;
DE   Contains:
DE     RecName: Full=Sarcosine reductase complex component B alpha chain;
GN   Name=grdG;
OS   Peptoclostridium acidaminophilum (Eubacterium acidaminophilum).
OC   Bacteria; Firmicutes; Clostridia; Eubacteriales; Peptostreptococcaceae;
OC   Peptoclostridium.
OX   NCBI_TaxID=1731;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RC   STRAIN=ATCC 49065 / DSM 3953 / al-2;
RA   Sonntag D., Soehling B., Andreesen J.R.;
RL   Submitted (AUG-1998) to the EMBL/GenBank/DDBJ databases.
CC   -!- FUNCTION: In the first step of sarcosine reductase, the substrate is
CC       bound to component PB via a Schiff base intermediate. Then the PB-
CC       activated substrate is nucleophilically attacked by the selenol anion
CC       of component PA to transform it to a carboxymethylated selenoether and
CC       the respective amine. By action of component PC, acetyl phosphate is
CC       formed, leaving component PA in its oxidized state. Finally component
CC       PA becomes reduced by the thioredoxin system to start a new catalytic
CC       cycle of reductive deamination.
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   -!- SUBUNIT: Heterotetramer of two alpha and two beta subunits. Component
CC       of the sarcosine reductase complex, together with components A and C.
CC       PB is substrate specific.
CC   -!- PTM: The peptide chain is cleaved into beta and alpha chains, and the
CC       alpha chain N-terminal cysteine is deaminated and oxidized to form a
CC       reactive pyruvoyl group. {ECO:0000250}.
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DR   EMBL; Y17872; CAA76906.1; -; Genomic_DNA.
DR   PIR; T08626; T08626.
DR   AlphaFoldDB; O86185; -.
DR   GO; GO:0033794; F:sarcosine reductase activity; IEA:UniProtKB-EC.
DR   InterPro; IPR016585; Gly/sarc/bet_Rdtase_B_asu/bsu.
DR   InterPro; IPR015417; Gly_reductase_pB_sua/b.
DR   Pfam; PF09338; Gly_reductase; 1.
DR   PIRSF; PIRSF011588; Gly_sarc_betain_red_a/b; 1.
PE   3: Inferred from homology;
KW   Oxidoreductase; Pyruvate.
FT   CHAIN           1..241
FT                   /note="Sarcosine reductase complex component B beta chain"
FT                   /evidence="ECO:0000250"
FT                   /id="PRO_0000045762"
FT   CHAIN           242..428
FT                   /note="Sarcosine reductase complex component B alpha chain"
FT                   /evidence="ECO:0000250"
FT                   /id="PRO_0000045763"
FT   MOD_RES         242
FT                   /note="Pyruvic acid (Cys)"
FT                   /evidence="ECO:0000250"
SQ   SEQUENCE   428 AA;  46694 MW;  430D9A23AE3D68D3 CRC64;
     MRLELGKIFI KDVQFGEKTT VEKGVLYVNK QEIIDLAMQD DRIKSVNVEL ARPGESVRIA
     PVKDVIEPRV KVEGSGAMFP GMTNKVKTVG SGRTHALVGS TVLTCGKIVG FQEGVIDMSG
     PIAKYCPFSE TNNVCIVVEP VEGLETHAYE AAARMVGLKA AEYVGKAGLD VEPDEVVVYE
     TKPLLEQIKE YPDLPKVAYV HMLQSQGLLH DTYYYGVDAK QFIPTFMYPT EIMDGAITSG
     NCVAPCDKVT TFHHLNNPVI EDLYKRHGKD LNSVGVILTN ENVYLADKER CSDMVGKLVE
     FLGIDGVLIT EEGYGNPDTD LMMNCKKCTQ AGAKVVLITD EFPGRDGKSQ SVADATPEAD
     AVASCGQGNL IEHFPAMDKV IGMLDYVETM IGGYKGCINE DGSFDAELQI IIASTIANGY
     NKLTARFY