KEGG   ENZYME: 1.21.4.4Help
Entry
EC 1.21.4.4                 Enzyme                                 

Name
betaine reductase;
acetyl-phosphate trimethylamine:thioredoxin disulfide oxidoreductase (N,N,N-trimethylglycine-forming)
Class
Oxidoreductases;
Catalysing the reaction X-H + Y-H = X-Y;
With a disulfide as acceptor
BRITE hierarchy
Sysname
acetyl-phosphate trimethylamine:thioredoxin disulfide oxidoreductase (betaine-forming)
Reaction(IUBMB)
acetyl phosphate + trimethylamine + thioredoxin disulfide + H2O = betaine + phosphate + thioredoxin [RN:R07228]
Reaction(KEGG)
Substrate
acetyl phosphate [CPD:C00227];
trimethylamine [CPD:C00565];
thioredoxin disulfide [CPD:C00343];
H2O [CPD:C00001]
Product
betaine [CPD:C00719];
phosphate [CPD:C00009];
thioredoxin [CPD:C00342]
Comment
The reaction is observed only in the direction of betaine reduction. The enzyme from Eubacterium acidaminophilum consists of subunits A, B and C. Subunit B contains selenocysteine and a pyruvoyl group, and is responsible for betaine binding and trimethylamine release. Subunit A, which also contains selenocysteine, is reduced by thioredoxin, and is needed to convert the carboxymethyl group into a ketene equivalent, in turn used by subunit C to produce acetyl phosphate. Only subunit B distinguishes this enzyme from EC 1.21.4.2 (glycine reductase) and EC 1.21.4.3 (sarcosine reductase).
History
EC 1.21.4.4 created 2003, modified 2010
Orthology
K10672  
betaine reductase
Genes
PPR: 
DDS: 
SAT: 
DTI: 
CBO: 
CBO1261(grdA)
CBA: 
CLB_1290(grdA)
CBF: 
CLI_1346(grdA)
CLJ: 
CLD: 
CACE: 
AMT: 
AOE: 
CDF: 
CDL: 
PDF: 
CST: 
STH: 
DOR: 
EAC: 
TTE: 
TTE1874(PlsX2) TTE1875(FabH4)
CHY: 
CHY_2392(grdA) CHY_2394(grdC)
NTH: 
AAR: 
FMA: 
SHI: 
TDE: 
TDE0239(grdD) TDE0240(grdC) TDE0745(grdA)
TAI: 
 » show all
Taxonomy
Reference
1  [PMID:10091582]
  Authors
Wagner M, Sonntag D, Grimm R, Pich A, Eckerskorn C, Sohling B, Andreesen JR.
  Title
Substrate-specific selenoprotein B of glycine reductase from Eubacterium acidaminophilum. Biochemical and molecular analysis.
  Journal
Eur. J. Biochem. 260 (1999) 38-49.
  Sequence
Reference
2  [PMID:11422384]
  Authors
Bednarski B, Andreesen JR, Pich A.
  Title
In vitro processing of the proproteins GrdE of protein B of glycine reductase and PrdA of D-proline reductase from Clostridium sticklandii: formation of a pyruvoyl group from a cysteine residue.
  Journal
Eur. J. Biochem. 268 (2001) 3538-44.
Other DBs
ExplorEnz - The Enzyme Database: 
IUBMB Enzyme Nomenclature: 
ExPASy - ENZYME nomenclature database: 
BRENDA, the Enzyme Database: 
CAS: 
125752-87-6

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